Shizue Izawa is a former Japanese human, later an “flame majin,” and a legendary adventurer known as the “Conqueror of Explosions” in That Time I Got Reincarnated as a Slime, whose short encounter with Rimuru Tempest becomes one of the core turning points of his life and identity.
Shizue Izawa is originally an 8‑year‑old girl from wartime Tokyo who is summoned to another world by the demon lord Leon Cromwell during an air raid.
Mortally burned and on the verge of death, she survives thanks to her innate resistance to fire and Leon’s decision to forcibly fuse her with the upper spirit Ifrit.
Over decades she lives as a wandering adventurer and later as a teacher, becoming a famed hero known as the “Conqueror of Explosions.”
Her outward appearance stops in her late teens, but her true age by the time she meets Rimuru is around 70.
She is the first otherworlder Rimuru meets after his reincarnation and the model for his human form.
Her death, and her decision to have Rimuru devour her, deeply shapes his values, appearance, and several of his later bonds and grudges.
Name: Shizue Izawa
Species: Human → Flame Majin (flame demonized human / person possessing a flame spirit)
Origin: Earth (Japan, Tokyo during World War II)
Status: Deceased (soul resides peacefully within Rimuru)
Title: Conqueror of Explosions
Blessing: Blessing of a Demon Lord (from Leon Cromwell)
Age: Appears around 16–17; actual age roughly 70 at time of death
Occupation(s): Adventurer, Hero, Instructor (combat and magic teacher in the Kingdom of Ingracia)
First Appearance (story): Main series, Volume 1
Shizue appears as a delicate, almost fragile beauty in her mid‑teens with black hair and black eyes, reflecting her Japanese origin.
Her body is marked by extensive burn scars from the Tokyo air raid, scars that never disappear even after becoming a flame majin.
Because of these scars and the danger posed by Ifrit within her, she habitually wears an anti‑magic mask that suppresses the spirit and hides much of her face.
When Rimuru later copies her form, he notes that beneath the mask she is an extremely beautiful girl.
Her physical growth stops at around 16–17 due to her fusion with Ifrit.
In the web version of the story, she eventually appears as an old woman, but in the light novel and anime her body remains youthful even as her soul ages.
Shizue is outwardly calm, gentle, and reserved, especially after years of suppressing her emotions to survive Ifrit’s possession and the trauma of her past.
Underneath this calm lies deep sorrow, guilt, and a complex resentment toward Leon Cromwell, who summoned and “used” her.
She carries a strong sense of responsibility and a desire to protect the weak, inspired by the hero who rescued her from Leon’s castle.
This leads to her long career as a heroic adventurer and later as a teacher who cares deeply for her students.
Despite being hailed as a hero, she is modest and avoids calling herself a “hero” in the same sense as the black‑silver‑haired girl who saved her.
She tends to bottle up her pain, quietly accepting burdens alone, yet she is affectionate and gentle with children and students.
By the time she meets Rimuru, she has accepted that her life is near its end and is driven by a mixture of unresolved resentment, lingering hope, and a final determination to settle things with Leon.
Her final words and actions show a yearning to be remembered: she wants someone to know that “a person like me existed.”
Shizue’s powers come from a combination of her Earth‑born resistance, Leon’s blessing, and her fusion with Ifrit.
Blessing of a Demon Lord (Leon Cromwell’s blessing):
Grants her enhanced abilities and potential, supporting her growth into a top‑class adventurer and hero.
Core Magic Types:
Elemental Magic
Spirit Magic
Summon Magic (especially summoning/using Ifrit)
Unique Skill – “Shapeshifter” (“Utsurou Mono” / “The One that Changes”):
A unique skill she later passes on to Rimuru when he devours her.
This skill influences Rimuru’s ability to change and evolve, intertwining their fates.
Extra Skills:
Flame Manipulation
Explosion
Heat Wave
Magic Sense
Resistances:
Complete immunity to fire and heat attacks
High resistance to physical attacks
Ifrit Fusion:
As Ifrit’s host, she can wield tremendous firepower, commanding intense flames and explosive attacks that earn her the title “Conqueror of Explosions.”
However, the mismatch between her hatred for Leon and Ifrit’s devotion to him causes internal conflict, shortens her lifespan, and makes full cooperation impossible.
Swordsmanship:
Trained by a black knight in Leon’s castle, Shizue becomes an elite swordswoman.
Unlike Ifrit, who cannot use a sword, her sword skills are purely her own talent and hard work, complementing her magic.
Even among adventurers, she is considered top tier, rivaling heroes in battle capability.
Her legend as a flame spirit user and hero spreads across countries.
Earth: Childhood in Wartime Tokyo
Shizue spends her early years in Tokyo during World War II, living alone with her mother after her father goes to war before she is old enough to remember his face.
They have no reliable relatives, leaving the two to rely only on each other.
During the Tokyo air raid, she is caught in the bombing and consumed by flames, suffering devastating burns.
As she is about to die, she is suddenly summoned to another world by the demon lord Leon Cromwell.
The trauma of being burned alive imprints a deep fear and rejection of fire in her soul.
From this, she gains natural fire resistance abilities: heat manipulation and immunity to fire attacks, which later allow her to survive fusion with Ifrit.
Early Years in Leon’s Castle
Summoning and Abandonment
Leon’s summoning was meant for some other, more specific existence, and Shizue appears only as a “failure” in his eyes.
Badly burned and just a child, she is coolly judged and essentially left to die, an indifference that scars her heart as deeply as her physical burns.
When she begs for help, Leon, either out of whim or cold calculation, notices her fire resistance.
He decides to forcibly fuse her with Ifrit, an upper spirit of fire, using her as a vessel and tool.
This act saves her life but also binds her to a dangerous being whose loyalty lies entirely with her summoner.
From this point, her hatred and resentment toward Leon begin to take root.
Naming and Early Possession
Leon gives her the name “Shizue,” and from then on she becomes his flame majin.
At first, Ifrit almost completely controls her body, using her to mercilessly incinerate enemies and threats.
Ifrit manipulates her emotions, numbing fear and anxiety so she does not go mad from the horror of what she is forced to do.
Shizue’s mind is half‑asleep, functioning by habit and numbness, just barely surviving within her own body.
A Friend’s Death
Years later, Shizue regains some autonomy and learns the sword from a black knight serving Leon.
During this period, she befriends a girl named Pirino and a magical beast resembling a fox, known as a wind fox.
Unaware of the danger of naming monsters, Shizue and Pirino name the wind fox “Piz.”
When Pirino introduces Piz to Leon, the monster becomes violently agitated in his presence.
Ifrit interprets Piz’s behavior as an insult and threat to Leon and acts without mercy.
Using Shizue’s body, Ifrit forces her to burn both Piz and Pirino to death.
The trauma of killing her dear friend with her own hands shatters Shizue.
She is so devastated that she stops even being able to cry, burying her pain deep inside as she continues to exist in a half‑numb state.
Youth: Encounter with the Hero and Escape
Battle with the Hero
Eventually, a black‑silver‑haired girl known only as the Hero attacks Leon.
Leon escapes, leaving Shizue behind like disposable bait.
Shizue, acting as a majin warrior, confronts the Hero but is defeated.
Ifrit exhausts massive amounts of magicules in the battle and falls asleep, leaving Shizue powerless and unable to fight.
The Hero, rather than killing her, questions why she is in such a place.
Hearing Shizue’s story, the Hero believes her and chooses to protect her instead.
Protection and the Anti‑Magic Mask
The Hero takes Shizue under her wing and gives her a special anti‑magic mask with extraordinarily high resistance to magic.
The mask suppresses Ifrit’s consciousness, allowing Shizue to regain her emotions and personality.
At first she can only talk freely with the Hero, remaining fearful and tongue‑tied around others.
Nonetheless, under the Hero’s protection she slowly recovers emotionally.
The Hero later introduces Shizue to the Adventurers’ Guild–like “Adventurer Mutual Assistance Association.”
There Shizue begins training in spirit magic under the Hero’s guidance and becomes famous as a powerful spirit user.
Adventuring with the Hero
Shizue fights alongside the Hero, gradually earning the epithet “Conqueror of Explosions” for her control over flame and explosive magic.
She reaches a level where the Hero recognizes her as a proper partner.
These years traveling with the Hero are the happiest of her life.
Shizue finds purpose: to help the poor, protect the weak, and emulate the Hero who saved her.
After the Hero: Solo Heroic Career
Parting from the Hero
After several years, Shizue’s body stops aging at around 16–17 due to Ifrit’s influence.
Eventually, the Hero departs on her own, leaving Shizue behind.
Shizue had always known they would separate someday, since she herself intended to seek Leon again to ask him about his motives.
She sees the Hero off and then begins travelling widely, offering help to people suffering under monsters or other threats.
Her deeds lead people to call her a hero, although she personally avoids taking that title, feeling she falls short of the standard set by the Hero who saved her.
Nevertheless, among nations and adventurers, she is known as a legendary figure.
Encounter with “Kuro” (Noir‑like Demon)
At one point, Shizue is pressured by a kingdom into joining a mission to subjugate a demon.
There she confronts “Kuro,” a demon whose overwhelming power terrifies everyone present.
The demon is intrigued by Shizue’s mask and its unique properties.
Instead of killing her, he spares her, on the condition that she keep what happened a secret.
To the outside world, the kingdom declares that the demon was repelled thanks to Shizue’s efforts.
In reality, they were merely spared, and Shizue reluctantly plays along with the cover story.
She privately worries and hopes that someday someone will deal with this demon.
Later spin‑off depictions show Kuro occasionally reappearing to Shizue, sometimes even fighting alongside her, weaving a strange long‑term connection between them.
Instructor Era: Teaching in the Kingdom of Ingracia
Feeling Old
Over time, even though Shizue’s body does not visibly age, her soul and mind grow old.
During a dragon‑subjugation mission, she realizes that her magic power is decreasing and she is less able to fully suppress Ifrit.
Recognizing her declining strength, she retires from front‑line adventuring.
She moves to the Kingdom of Ingracia, where she becomes an instructor teaching combat techniques and magic to younger adventurers.
Two Talented Students: Yuuki and Hinata
In the Ingracia headquarters of the Adventurer Mutual Assistance Association, Shizue meets two gifted otherworlder students: Yuuki Kagurazaka and Hinata Sakaguchi.
Yuuki is cheerful and optimistic, while Hinata is introverted and suspicious of others.
Shizue feels a special affinity for Hinata, sensing similarities in their painful circumstances and origins.
However, Hinata, fearful of being betrayed, leaves Shizue before fully opening up to her.
Shizue wants to chase after Hinata but is constrained by her responsibilities.
Yuuki is creating a new kind of organization, and Shizue increasingly serves as a negotiator and representative, tying her down.
Years later, she hears that Hinata has risen to an important position within the church.
Unable to meet her, Shizue nevertheless feels genuine joy and silently prays for her student’s safety.
Teaching the Summoned Children
Later, Shizue takes on a group of five young children who, like her, were forcibly summoned from another world.
Due to the raw power of the spirits implanted in them, their lifespans are drastically shortened; without intervention, they will die soon.
Shizue realizes that she has somehow escaped the same fate despite sharing their situation at the same age.
Suspecting that Leon and Ifrit may be the key to this contradiction, she decides to search for a way to save the children.
She entrusts the children to Yuuki’s care and resolves to go on one final journey.
Her destination: Leon Cromwell, to demand answers and a method to save the children—even if only to ask “why” he did all this to her.
Final Journey and Meeting Rimuru
Through the Jura Forest
Around the time Veldora Tempest disappears from the Jura Forest, Shizue needs to cross that same region.
There she encounters three B‑rank adventurers: Ellen and her companions.
Despite their rank, Shizue quickly notices that their fundamental adventurer basics are sloppy and incomplete.
This is partially due to Ellen’s noble upbringing and the fact that the two men are elite knights whose raw power is sealed, leaving their “adventurer training” underdeveloped.
As they travel together, they are attacked by monsters and flee deeper into the forest.
This leads them to encounter a village of hobgoblins, which piques Shizue’s curiosity.
Arrival at the Future Jura Tempest Federation
Shizue accompanies Ellen’s group to the monster settlement that will become the Jura Tempest Federation.
There she meets Rimuru Tempest, then in his slime body, acting as the leader of the monsters.
Seeing a small but organized and peaceful town built by monsters surprises Shizue.
Her conversation with Rimuru, especially about games and cultural references, leads her to realize he is an otherworlder from the same Japan as her.
They spend a brief, peaceful time together.
Shizue tells Rimuru about her background, and Rimuru sees in her a senior from his own world and a fragile yet strong person he quickly comes to respect.
Ifrit’s Rampage and Shizue’s Liberation
Suddenly, Ifrit breaks free from Shizue’s weakening control.
He seizes her body and goes on a rampage, attacking the village.
A fierce battle ensues between Ifrit‑controlled Shizue and Rimuru’s forces.
Ultimately, Rimuru uses his skill “Predator” to capture and devour Ifrit, ending the rampage and freeing Shizue from her long imprisonment.
Without Ifrit’s sustaining power, Shizue’s body rapidly begins to age and deteriorate.
She falls into a coma and remains unconscious for about a week.
When she awakens, she is physically weakened and understands that her remaining time is very short.
She calmly accepts this and prepares to face her end.
Final Wish and Being Devoured by Rimuru
Rimuru shares his memories of Japan with Shizue, including mental images of her hometown restored after the war.
She reveals her real name from Earth and feels a deep sense of closure.
Shizue then makes a final, very personal request: she asks Rimuru to devour her.
She does not want to die and become just a part of this foreign world’s soil; she would rather live on inside someone from her own world.
Rimuru initially refuses, horrified at the idea of consuming a friend’s body.
Yet Shizue gently but firmly insists, saying she cannot bear to be absorbed by a world she both hates and cannot entirely forgive.
Moved by her plea, Rimuru agrees with great reluctance.
Using Predator, he devours Shizue’s body and soul, along with her skill “Shapeshifter” and her complex emotional legacy, including her unresolved feelings toward Leon and concern for the children.
During the process, Shizue experiences a dream: she reunites with the Hero and then sees her long‑lost mother.
Embraced by her mother’s warmth, Shizue’s soul falls into an eternal, peaceful sleep within Rimuru.
Rimuru silently vows that she will dream forever, never waking from her happiness.
From that point on, Rimuru’s human form is modeled almost entirely on Shizue’s appearance.
Rimuru’s “Fated Woman”
Although Shizue’s on‑screen time is relatively brief, her impact on Rimuru is enormous.
He refers to their shared time as a “sanctuary” in his heart, something he revisits emotionally whenever he feels lost.
Rimuru’s human appearance, his connection to the summoned children, and several of his grudges and alliances all trace back to Shizue.
An in‑story fortune teller even describes her as Rimuru’s “fated person.”
He inherits not only her looks but also her skill “Shapeshifter,” her unresolved ties with Leon and the demon Kuro, and above all, her wish to save the five children.
Rimuru rarely tells others that he literally devoured her, fearing misunderstandings; only a few know the truth.
Ifrit After Shizue
Ifrit, once a subordinate to Ramiris and later captivated by Leon, strongly revered Leon Cromwell.
This devout loyalty clashed violently with Shizue’s resentment toward Leon, making their compatibility extremely poor.
According to Veldora Tempest, if Shizue and Ifrit had truly come to understand each other and aligned their hearts, their power would have multiplied several times over.
In that scenario, Shizue might have lived far longer and walked a completely different path.
After being devoured by Rimuru, Ifrit eventually reappears and gains a physical body as a subordinate of Veldora in the light novel Volume 11.
In Veldora’s “Slime Observation Diary,” Ifrit reflects on his past and deeply regrets never trying to reconcile with Shizue, especially over the killing of her friend Pirino.
Role in Rimuru’s Inner World
Shizue continues to appear within Rimuru’s mental world and dreams.
In Volume 4, she communicates her lingering worries about the children, especially Chloe Aubert, urging Rimuru to protect them.
By Volume 11, she is able to reunite with Hinata Sakaguchi and Chloe within these spiritual or mental spaces.
These meetings offer a kind of delayed emotional resolution for teacher and students.
Rimuru’s ongoing reverence for her memory means that whenever he thinks of Shizue, he tends to idealize her.
Later, when Ellen and the children share more candid stories about Shizue’s quirks and not‑so‑perfect sides, the contrast makes Rimuru laugh, cry, and feel closer to her than ever.
Rimuru Tempest
Rimuru is the slime protagonist who later takes on a human form based on Shizue’s appearance.
Shizue is the first otherworlder he meets, and their connection becomes foundational for his identity.
She entrusts Rimuru with three key legacies:
1) The rescue of her five summoned students.
2) Her unresolved ties and feelings toward Leon Cromwell.
3) Her own body, appearance, and Unique Skill, all taken into Rimuru through Predator.
Rimuru cherishes her memory deeply and views her as irreplaceable in his heart.
He keeps the fact that he devoured her body secret from most people to avoid misunderstandings.
Leon Cromwell
Leon is the demon lord who summons Shizue from Earth, treating her initial appearance as a failed result.
He saves her only incidentally by noticing her fire resistance and fusing her with Ifrit.
His true motives for summoning Shizue, abandoning her, and later actions remain unclear for much of the story.
Shizue’s desire to question his intentions is one of the main reasons for her final journey.
Rimuru later inherits this unresolved relationship, becoming entangled with Leon both because of Shizue and his own evolving role in the world.
Ifrit
Ifrit is an upper fire spirit who originally served Ramiris, one of the oldest demon lords.
Eventually impressed by Leon, Ifrit switches allegiance and becomes Leon’s subordinate.
He possesses Shizue as his host, giving her immense firepower but constantly clashing with her emotionally.
His fervent loyalty to Leon directly opposes Shizue’s anger and resentment toward the demon lord.
This internal incompatibility accelerates Shizue’s exhaustion and shortens her lifespan.
After being devoured by Rimuru, Ifrit later gains a body and becomes one of Veldora’s followers, where he finally gains the distance and awareness to regret his past treatment of Shizue.
Yuuki Kagurazaka
Yuuki is one of Shizue’s brightest students in the Kingdom of Ingracia, a fellow otherworlder from Japan.
To Shizue, he appears cheerful, positive, and full of promise.
She trusts him enough to leave the five summoned children in his care when she departs on her final journey.
Unbeknownst to her, Yuuki’s true nature is far more complex and darker than he lets on.
Hinata Sakaguchi
Hinata is another of Shizue’s students, also summoned from another world and burdened by trauma.
Shizue feels especially close to Hinata, sensing their similar scars and isolation.
However, Hinata’s deep distrust of others leads her to leave Shizue before fully bonding with her.
Shizue respects her choice, later rejoicing from afar when she hears that Hinata has risen to a high rank in the church.
Long after Shizue’s death, Hinata encounters her again in a spiritual or inner realm connected to Rimuru.
This delayed reunion allows some emotional closure between teacher and student.
The Five Children: Kenya, Ryota, Gale, Alice, Chloe Aubert
The five summoned children are Shizue’s final class.
Each has a powerful spirit inside them, shortening their lifespan drastically.
Seeing her own 8‑year‑old self reflected in them, Shizue becomes determined to find a way to extend their lives.
She leaves them in Yuuki’s care and sets out to confront Leon, hoping to find a solution.
After her death, Rimuru takes on her wish and responsibility.
He ultimately manages to save the children, particularly Chloe, who later becomes deeply tied to both Shizue’s and Rimuru’s destinies.
The Hero Who Saved Shizue
This black‑silver‑haired Hero defeats Leon in battle and forces him to flee, unintentionally leaving Shizue behind.
Instead of finishing her off, the Hero questions Shizue, hears her story, and decides to rescue her.
The Hero gives Shizue the anti‑magic mask that suppresses Ifrit and becomes her guardian and mentor.
Although the Hero eventually leaves on her own journey, her influence shapes Shizue’s entire adult life and sense of justice.
The same mask is later passed from Shizue to Rimuru, and from Rimuru to Chloe.
Over time, the mask becomes a symbolic thread connecting the Hero, Shizue, Rimuru, and the summoned children across time.
Kuro (Noir‑like Demon)
“Kuro” is a powerful demon Shizue encounters during an “exorcism” mission pressed upon her by a kingdom.
He is fascinated by Shizue’s mask and its unusual properties and chooses to spare her.
The world later believes Shizue repelled the demon, but in truth Kuro simply let her go.
Shizue agrees to keep the truth secret, hoping that someday someone else will find a way to deal with him.
In some spin‑off depictions, Kuro appears repeatedly in Shizue’s life, sometimes as an uneasy ally.
This foreshadows the later importance of a certain primordial demon in the main story, tying Shizue’s past to future events.
That Time I Got Reincarnated as a Slime: The Slime Diaries
In The Slime Diaries, the timeline has already passed Shizue’s death, but she returns temporarily during an Obon‑like episode as a ghost.
She can observe Rimuru and the others but is invisible to most.
She continues to call Rimuru “Mr. Slime,” a gentle echo of their first meeting.
Watching him happily using her appearance to live among his friends pleases her—until she sees him being forced into a bunny‑girl outfit, which leaves her speechless.
Ellen and the others occasionally dream of Shizue in odd contexts, joking that maybe she had certain “unexpected hobbies.”
Meanwhile, Shizue, hearing this in ghostly form, panics at the “slander” and “reputation damage” it causes her image.
Because of these recurring gags, she becomes a “martyr regular” rather than a standard recurring character, constantly getting dragged into comedic misfortune.
Rimuru’s idealized image of her often clashes with the more human, teasing stories told by her old friends and students, leading to both humor and bittersweet moments.
Flower Knight Girl Collaboration: “If I Got Reincarnated as a Flower Knight”
In the collaboration with Flower Knight Girl, Shizue appears as a flower knight unit under the name “Dodantsutsuji” (based on the Enkianthus / Dodan‑Tsutsuji shrub).
Upon arriving in the flower knight world by coincidence, she notes that it is a pleasant place to live.
Her associated flower meanings include “self‑control,” “return of kindness,” “elegance,” and “receive my feelings.”
While she finds the first two fitting, being called “elegant” embarrasses her, as she is unused to such compliments.
In that game’s event story, she joins the party in the second half of the scenario.
Players can recruit her by progressing through to episode 6 of the event at the time of the collaboration’s original run.
She has a rarity‑upgrade (blooming) path to ★6, which significantly boosts her power.
However, upgrading her triggers additional equipment slot unlock requirements that cost special items, so players must weigh team composition and resource use before deciding.
In this story, Shizue also acquires the in‑world name “Dodantsutsuji,” though the exact circumstances of this naming are not fully explained.
Rimuru also appears in the Flower Knight world, raising anticipation about how and when the two will reunite in that setting.
A special skin allows players to switch Shizue to her masked version, reflecting her original appearance from the main series.
The collaboration event is not currently set for rerun, and the developers have explicitly stated that the event will not be revived, making her unit and story uniquely time‑locked.
Granblue Fantasy Collaboration: “The Blue Skies’ Wedge”
In the Granblue Fantasy collaboration event “The Blue Skies’ Wedge,” Shizue herself does not physically appear.
However, she is indirectly referenced when Galleon asks Rimuru to take his slime form, and he mentions someone whose appearance he uses.
Her influence thus extends even into cross‑game events through Rimuru’s constant use of her likeness.
Although unseen, she remains a quiet but pivotal presence behind Rimuru’s identity in collaborative stories as well.
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