Kizuna Hida

Kizuna Hida is a member of the Japanese Mega Float hybrid gear team Amaterasu, where he serves as its rookie captain.

He pilots the Heart Hybrid Gear Eros, a unit famous both for its unusual abilities and for the embarrassment that comes with shouting its name during activation.

He is the son of Nayuta Hida, the developer of Heart Hybrid Gear technology, and the younger brother of Reiri Hida, the commander-in-chief of Ataraxia.

Although he once lived alone in Tokyo Float, he is forcibly transferred to Ataraxia in his second year of high school after Reiri discovers the true nature of his Gear.

Kizuna is also known by several epithets, including Limit Breaker, The Demon King of Lemuria, and Eros Demon King.

His reputation grows dramatically over the course of the story, especially after he begins fighting directly on the front lines.

Name: Kizuna Hida

Gender: Male

Birthplace: Tokyo Metropolis

Affiliation: Mega Float Japan, Ataraxia High School Combat Department, Second-Year Class A

Unit: Amaterasu

Position: Captain

Heart Hybrid Gear: Eros

Nicknames and Titles: Limit Breaker, The Demon King of Lemuria, Eros Demon King

Birthday: September 10

Height: 173 cm

Blood Type: A

Hobby: B-grade gourmet food

Favorite Food: Beef bowl

Voice Actor: Kenji Akabane

Childhood Voice Actor: Kimi Kimura

Kizuna is serious, responsible, positive, and deeply considerate of others.

He has the kind of straightforward kindness and common sense that make him feel every bit like a classic heroic lead.

At the same time, he is also a long-suffering straight man constantly dragged into absurd situations by the people around him.

Because of Eros’s nature, he is pushed into intimate situations with female teammates as part of their combat support system, even though he personally finds much of it awkward and excessive.

This leaves him in an unfair position.

Many girls look down on him, while many boys envy him, though some male students also idolize him because of his notoriety and the public release of the girls’ body data.

Despite that, Kizuna treats his role with complete sincerity.

Once he learns the secret behind the Lost Series, he becomes determined to protect both his teammates and the world, no matter how uncomfortable or humiliating the process may be.

He is notable for his emotional maturity.

When others are vulnerable, he listens without judgment, supports them gently, and often shows a depth of trust and courage that wins people over.

Even in intimate enhancement procedures, he tries to respect his partner’s feelings and act with composure rather than selfish desire.

That self-control becomes one of his defining strengths.

As a child, Kizuna underwent internal surgery performed by his mother, who implanted a Heart Hybrid Gear into his body.

He then spent his early years as a test subject in Ataraxia’s laboratory, which later became Nayuta Lab.

He was unable to attend school and lived almost entirely as part of his mother’s research.

Still, young Kizuna was happy to help because he believed he was being useful to her.

That changed seven years before the main story.

After Nayuta discovered a girl with even greater aptitude for Heart Hybrid Gear, Aine Chidorigafuchi, she abruptly lost interest in Kizuna and had him removed from the laboratory.

After Nayuta’s disappearance, Kizuna lived with Reiri in Tokyo Float.

When Reiri entered Ataraxia, he was left to live alone until she later summoned him and forced him into the academy.

His history with his mother leaves complicated emotional scars.

Reiri came to hate Nayuta intensely for what happened, while Kizuna himself remained conflicted until later confronting her and finally severing that bond emotionally.

Kizuna’s arrival at Ataraxia is anything but normal.

Because his core’s properties make him essential to the combat efficiency and survival of the female Gear users, Reiri actively encourages what she bluntly frames as improper relationships between him and the team members.

He is given a mobile terminal that also functions as a student ID and displays the members’ profiles and hybrid counts.

To make “accidents” more likely, he is even placed in the girls’ dormitory, with his room lock deliberately disabled by Reiri.

Kizuna himself is uncomfortable with these arrangements.

Still, once he understands the stakes, he starts seriously searching for the most efficient methods of Heart Hybrid enhancement, even if everyone around him is horrified by how earnest he is about it.

Over time, his honesty, bravery, and readiness to put himself in danger for others gradually earn the trust and affection of the entire Amaterasu team.

He eventually forms deep bonds not only with his allies, but even with female magic knights from the opposing side under special circumstances.

According to the source material, he ultimately performs enhancement acts with a total of twenty-five partners.

These encounters are framed not as casual indulgence, but as a necessary means of strengthening and saving others.

At first, Kizuna is not an impressive direct combatant.

Because Eros has weak offensive armament and comparatively low output, he mainly supports others by deploying barriers and restoring teammates’ hybrid counts through the LOVEROOM system.

Later, after being captured by the forces of Batranthis and escaping back to his side, he begins fighting on the front lines more frequently.

This change happens partly because of a shortage of combat personnel and partly because his own abilities become much more dangerous.

Kizuna never hesitates when an ally is in trouble.

If someone is in danger, he steps forward immediately, even if it means taking the risk himself.

He is willing to strike with full force in battle regardless of whether the enemy is female.

Given that nearly every combatant around him is a woman, that practicality becomes unavoidable.

His growing strength and versatility eventually make him terrifying to the enemy.

The Batranthis side comes to fear him as The Demon King of Lemuria.

General Characteristics

Kizuna’s Gear is called Eros.

That fact alone causes him endless embarrassment, because activating a Heart Hybrid Gear requires the user to shout its name aloud.

In other words, every transformation demands that he yell “Eros!” at full volume.

He initially refused to equip it for exactly that reason.

Compared with other units, Eros has a relatively simple design.

Its main body color is black, and its core glows pink.

Its major strengths are low hybrid count consumption and long-lasting barrier deployment.

Its main weakness is poor offensive armament and much lower raw output than most other units.

Eros is unique in another way as well.

Unlike the cores used by other units, which originate from another world, the core of Eros was discovered on Earth and can only be installed in a male user.

Heart Hybrid Functions

The signature ability of Eros is Heart Hybrid, which allows Kizuna to restore a partner’s hybrid count through sexual contact.

As absurd as it sounds, this process is treated as a life-or-death necessity in the story, because a user whose count drops to zero may in the worst case die.

Another ability is Climax Hybrid, a powerful enhancement triggered by an extreme state of excitement.

There is also Connective Hybrid, performed with multiple people, and Kiss Charge Hybrid, which imposes a heavy burden but grants explosive amplification.

Because these scenes are too extreme for ordinary television presentation, the anime adaptation heavily obscures much of the imagery through visual censorship.

That result is treated almost as an inevitability.

Weapon Copying

Eros possesses another crucial trait.

When Kizuna performs a Climax Hybrid with a partner, he can replicate that partner’s weapon system and use it himself.

This ability radically expands his combat potential.

As his relationships deepen, so does his arsenal, and his battle power rises accordingly.

That escalation is a major reason he transforms from a support specialist into a frontline terror.

By the later stages of the story, he is no longer just a strange support unit but a feared powerhouse.

Mode Zeros

This form uses the power of Aine Chidorigafuchi’s Gear, Zeros.

It greatly boosts Eros’s overall performance, especially speed and close-quarters combat capability.

Mode Cross

This form uses the power of Yurishia Farandole’s Gear, Cross.

It allows Kizuna to summon a large number of firearms and overwhelm enemies with intense firepower.

Mode Neros

This form uses the power of Hayuru Himekawa’s Gear, Neros.

It manifests a massive blade capable of delivering powerful slashing attacks.

Mode Talos

This form uses the power of Silvia Silkcut’s Gear, Talos.

It creates a giant hammer-like energy construct that crushes opponents with sheer force.

Mode Amaterasu

This form draws on the combined power of all members of Amaterasu.

Kizuna rapidly switches between weapons and unleashes a relentless chain of attacks.

Reiri Hida

Reiri is Kizuna’s older sister and the commander of Ataraxia.

She is the person who forcibly drags him into academy life and into his role as Amaterasu’s captain.

She is also the architect of many of the bizarre situations surrounding his dorm assignment and team interactions.

Although her methods are extreme, they are motivated by strategic necessity and by her desire to use his unique power to save others.

Nayuta Hida

Nayuta is Kizuna’s mother and the creator of Heart Hybrid Gear technology.

She treated him as a research subject in childhood and later discarded him after finding a more suitable candidate.

This abandonment shaped much of Kizuna’s emotional life.

He later confronts her directly and reaches a final emotional break with her.

Amaterasu

Kizuna’s bond with the members of Amaterasu is central to his development.

Though their relationship begins with suspicion, embarrassment, and conflict, his sincerity and determination eventually earn the affection of the entire team.

He becomes someone the others can rely on not just for power, but for emotional support.

That trust is one of the strongest themes surrounding his character.

One of Kizuna’s most unusual qualities is the clash between his personality and his role.

He is, at heart, a decent and earnest young man trapped inside a wildly indecent combat system.

That contrast gives him much of his appeal.

He is both a capable protector and a perpetual victim of humiliating circumstances.

His battle cry is famously awkward, his responsibilities are absurd, and his social situation is a disaster.

Yet he keeps going because people are counting on him.

“A girl is in danger. Of course I’m going.”

“If you ever feel like talking, don’t hold back. Talk to me, okay?”

“Eros!”