Yuuki Wakura

Name: Yuuki Wakura

Gender: Male

Age: 17

Height: 173 cm

Birthday: March 12

Blood Type: A

Occupation: Third-year student at Uenoge Public High School (at story start); later dorm manager for the Seventh Unit of the Demon Defense Force

Series: Chained Soldier

Voice Actor (main): Yuya Hirose

Voice Actor (childhood): Aya Suzaki

Skills: Housework, especially cooking and cleaning

Hobbies: Developing new recipes and inventing or improving cleaning tools

Yuuki is introduced as an ordinary high school senior living in a matriarchal, male-disadvantaging society and worrying about his future after graduation.

While lost in the otherworldly “Magic City,” he is attacked by monsters called Shuki and rescued by Kyouka Uzen, a top commander in the Demon Defense Force.

When the Shuki horde overwhelms them, Kyouka uses her ability “Everlasting Chains” to forcibly make Yuuki her “slave,” unlocking his hidden power and allowing him to annihilate the enemies.

After this incident, Yuuki is officially hired as Kyouka’s slave and as the live-in manager of the Seventh Unit’s dormitory, although he cannot become a formal member of the Demon Defense Force because men are not allowed to join.

At first, Yuuki dreams of becoming a hero within the Demon Defense Force and becoming popular with girls.

As the plot progresses and his missing sister reappears as a humanoid Shuki, his priorities shift toward saving her and other transformed humans rather than chasing popularity.

Yuuki is kind-hearted, earnest, and surprisingly domestic, thanks largely to the influence of his older sister Aoba Wakura, who drilled household skills into him.

He often acts as the emotional core of the Seventh Unit, caring about both his comrades and even enemy humanoid Shuki once he learns their circumstances.

He has a strong desire to be a “hero,” which initially comes with a comedic wish to “become super popular.”

Over time, his sense of heroism matures into a determination to shoulder responsibility and find a way to restore the lost humanity of the humanoid Shuki, including his sister.

Yuuki is also highly adaptable.

Through repeated “loan” transformations, he accumulates experience that strengthens both his body and mind, making him a uniquely fast-growing combat asset.

Yuuki has an older sister named Aoba Wakura, whom he deeply admires.

As children, they often played together by the Tama River; Aoba frequently made him cry, but he loyally followed after her anyway.

Six years before the main story, Aoba was lost during a Magic City disaster and presumed dead.

Yuuki’s parents eventually recovered from the incident and now live in their family home in Uenoge, where Yuuki grew up.

During a battle with a one-horned Shuki known as Kidoumaru, Yuuki sees a humanoid Shuki riding on Kidoumaru’s back whose appearance resembles Aoba, shocking him.

Later, during a second attack by humanoid Shuki, Yuuki is kidnapped to a hidden village where he finally reunites with Aoba face to face.

In the hidden village, Yuuki learns from Aoba about the truth and circumstances of the humanoid Shuki.

After the conflict there, he is forced to part ways with his sister again, but he vows to find a way to turn Aoba and the other humanoid Shuki back into humans.

Yuuki functions as the central viewpoint character through which readers learn about the gender-biased society, the Magic City, Shuki, and the Demon Defense Force.

Because he is technically “just” a slave and dorm manager rather than an official soldier, he occupies an unusual position: important to combat yet socially marginalized.

His power has no strict upper bound and grows through usage with multiple partners, making him a unique strategic resource whose potential attracts attention.

This leads characters like Touka Azuma and members of other units to view him as a “special existence” and a person worth recruiting or studying.

In a popularity poll, Yuuki placed seventh in the first round, which is notable considering he is surrounded by many flashy female characters.

Within the story, his presence increasingly influences the goals and emotional states of unit leaders, new heroines, and even enemy figures.

Everlasting Chains (Slave Form)

Yuuki’s main power comes from Kyouka Uzen’s ability “Everlasting Chains,” which transforms his body into a monstrous, Shuki-like form called his slave form.

To activate it, Yuuki kisses Kyouka’s hand, causing his body to morph into a powerful, inhuman shape with strength far beyond any normal human.

In slave form, Yuuki wears a collar with a chain attached to it.

The “rider” (the master holding the chain) mounts his back and, by pulling the chain and giving commands, can draw out even greater power from Yuuki.

In this state, Yuuki can easily exterminate dozens of regular Shuki in moments.

The form is highly versatile and functions as a “base form” that can evolve or branch into various specialized transformations depending on who holds his chain.

If Kyouka is absent, Yuuki can still force a partial transformation by kissing her items, such as her boot in her locker.

However, this partial slave form is unstable, with a shorter time limit and weaker performance; when he used this makeshift transformation to defeat a huge Shuki, the reward he received later from Kyouka was an extremely painful massage.

When the slave transformation is canceled, light or smoke bursts out as Yuuki returns to human form.

Yuuki has even used this flash of light and smoke as a makeshift smokescreen during a training match with the Sixth Unit.

A key implication of Everlasting Chains is that, if its description “draws out the power of the enslaved target” is taken literally, then all slave forms and loan-based transformations are originally latent abilities within Yuuki himself.

Because of this, Touka Azuma becomes interested in Yuuki’s high potential and considers drawing him into the Azuma family, while other unit members see him as an unusually special case.

Tenshin (Heavenly Advance)

“Tenshin” is an evolved, higher-stage version of the slave transformation, described as the further potential of Everlasting Chains.

When Yuuki uses Tenshin, his power and speed increase dramatically compared to pre-evolution forms, though his time limit becomes even shorter.

Yuuki first learns Tenshin through grueling training with Himari Azuma.

Initially, the overwhelming power makes the form hard to control, causing him to flounder and overexert himself, but he eventually masters it through additional training with Kyouka.

Currently, Tenshin has been explicitly shown for the base slave form and the “Whirlwind” form.

It is implied that some other forms may have their own Tenshin-style “Heaven” evolutions, further expanding Yuuki’s potential.

Loan-Based Derived Forms

Kyouka can “loan out” Yuuki’s slave form by transforming him, then having someone else grab his chain.

Yuuki’s body then changes into a new, specialized form tailored to the borrower’s ability, effectively a form-change system.

The original author has described this concept explicitly as transformation form changes.

Experience from these borrowed forms accumulates within Yuuki, strengthening his base form and improving his mental resilience.

Below are the known derived forms and their traits:

Whirlwind (Tsumujikaze) – Borrower: Himari Azuma

In Whirlwind form, Yuuki becomes leaner and wears an outfit reminiscent of a ninja.

This form excels in speed and agile movement, allowing rapid close-quarters attacks and high-speed techniques like “Brand-Breaking Strike.”

War Cloud (Ikusagumo) – Borrowers: Kyouka Uzen and Himari Azuma

War Cloud is activated when both Kyouka and Himari hold the chain at the same time.

Yuuki takes on the appearance of a heavily armored warrior with armor resembling a samurai and paper-like streamers for hair.

This form focuses on overwhelming power and battlefield control, using techniques such as a massive roar that sends destructive shockwaves.

It represents a synergistic power-up combining the authority of Kyouka and the adaptability of Himari.

Shining Star (Kira-Boshi) – Borrower: Nei Ōkawamura

In Shining Star form, Yuuki wears a smooth, rounded helmet and armor without protruding parts, giving him a sleek, sensor-like appearance.

His five senses—sight, hearing, and more—are greatly amplified for reconnaissance and detection.

He can even see through obstacles, gaining partial x-ray–style vision.

This form is primarily used for searching, tracking, and information gathering rather than direct brute-force combat.

Rock-Piercer (Iwatōshi) – Borrower: Shushu Suruga

Rock-Piercer form equips Yuuki with cube-shaped armor on his shoulders, emphasizing raw strength.

He becomes a power-focused brawler capable of launching energy blasts by concentrating power into his fists.

This form is suited for breaking through enemy defenses and delivering heavy, decisive blows.

It embodies the destructive impact associated with Shushu Suruga’s fighting style.

Phoenix Wing (Houyoku) – Borrower: Yakumo Ezo

Phoenix Wing gives Yuuki large wings and a streamlined body specialized for flight.

Working together with Yakumo Ezo’s own abilities, the form has flight speed exceeding even her solo capabilities.

This form excels at aerial combat, high-speed movement, and rapid deployment between positions.

It allows Yuuki to serve as both a flying mount and a high-mobility attacker.

Killing Fang (Koroshikiba) – Borrower: Ren Yamashiro

Killing Fang is a terrifying, berserk form where Yuuki’s entire body turns pitch black.

In this state he is driven by pure instinct, relentlessly slaughtering Shuki and even turning his fangs against Ren herself at times.

His regenerative capacity skyrockets in this form, instantly healing injuries inflicted by Ren’s punishments.

While incredibly dangerous and powerful, it is also unstable and difficult to control, making it a high-risk, high-reward transformation.

Flesh Shot (Nikuhazumi) – Borrower: Maki Toukaze

In Flesh Shot form, Yuuki sprouts horns like a bull and wears clothing reminiscent of ancient Greek attire.

His body becomes rubber-like, able to stretch and flex in unusual ways.

This elasticity grants high-impact, rebound-based attacks and grants him resistance to blunt force.

The form is well suited to dynamic, physical combat and close-range brawling.

Explosive Sound (Bakuon) – Borrower: Mira Kamiunten

Explosive Sound radically changes Yuuki into a large, two-wheeled motorcycle.

Mira rides him as the driver, using the transformation both as transportation and as a combat vehicle.

The roaring engine sound can be used to flush out hidden Shuki by startling or provoking them.

In addition, this form can breathe flames from its “mouth,” allowing for fiery offensive attacks.

Dominating Raiment (Hagoromo) – Borrower: Konomi Tatara

In Dominating Raiment, Yuuki becomes a suit of armor worn by Konomi Tatara instead of acting as a separate fighter.

This armor amplifies Konomi’s natural hand-to-hand combat abilities, increasing her offense and defense.

Yuuki’s own will remains active, meaning the armor can move independently when Konomi is injured or unable to fight.

This makes the form a hybrid between powered armor and a semi-autonomous partner.

Moon Concealment (Tsukigakure) – Borrower: Bell Tsukiyono

Moon Concealment grants Yuuki a camouflage ability similar to a chameleon.

While riding on Bell Tsukiyono, he can cloak both of them, turning them effectively invisible.

This form circumvents the limitation of Bell’s own ability, which normally requires her to touch a target for activation.

Together, they gain stealth and infiltration capacity that is far greater than either could achieve alone.

Guardian Dog (Komainu) – Borrower: Warwara Pilipenko

Guardian Dog coats Yuuki in overlapping metal plates, giving him the look of a powerful robot guardian.

His loyalty and devotion to Kyouka function as the energy source fueling this form.

Although his movement speed decreases somewhat, his strength reaches “super robot” levels.

He can even fire his fists as rocket punches and unleash the devastating “Sin-Erasing Light” to erase enemies on contact.

Mercy Rain (Jiu) – Borrower: Haruno Hisashige

In Mercy Rain, Yuuki takes on an ancient Chinese-inspired costume with flowing robes.

By rubbing his hands together, he can generate clouds that release healing rain.

The rain has restorative effects, healing allies within its range and supporting large groups at once.

This form is a rare support-oriented transformation focused on recovery instead of direct offense.

Unresolved Form – Borrower: Tenka Izumo

When Yuuki is loaned to Tenka Izumo, his transformation does not complete in a visible, stable form.

Instead, Yuuki suddenly experiences abnormal overheating in his body, and the process is interrupted before a clear new form appears.

This hints at some special interaction or incompatibility between Yuuki’s latent power and Tenka’s abilities.

The nature and true potential of this form remain uncertain and are treated as a mystery within the story.

Yuuki’s slave and loan forms come with numerous named attacks, many of which incorporate themes of slavery, brand, sin, or punishment.

Each technique reflects the nature of the form and sometimes the personality of the borrower.

Notable techniques include:

Brand-Breaking Strike (Rakuin-Ha)

Used in Whirlwind form.

Yuuki gathers power into his legs for extreme acceleration, then quickly shifts that power into his arms to deliver a high-speed palm strike to the enemy.

Roaring Blast (Houkou-Geki)

Used in War Cloud form.

Yuuki releases a powerful roar that manifests as a shockwave, damaging or repelling enemies in front of him.

Mighty Blade Cross (Goujin Cross)

Used in base slave form.

From above an enemy, Yuuki chops downward while Kyouka, riding his back, slashes horizontally, creating a cross-shaped attack that slices the enemy in two directions.

Slave Frame Fist (Reika Fist)

Used in base slave form.

Yuuki concentrates energy into his fist and delivers a devastating punch, emphasizing raw power.

Goat of Atonement

Used in Killing Fang form.

Yuuki manifests a crest in front of his targets; on his signal, a gigantic spectral goat bites down and crushes the upper bodies of marked enemies, and he can target multiple foes at once.

Slave-Edge Blade (Reijin no Tachi)

Used in the “Heaven” evolution of the base slave form.

Yuuki wraps the chain around Kyouka’s sword and fuses with the blade, transforming into living cutting power; as Kyouka swings, Yuuki is launched along with the slash, enabling powerful attacks and even rescuing allies absorbed by enemies, such as saving Mira from Soraori.

Sin-Erasing Light

Used in Guardian Dog form.

A basketball-sized ball of light appears from Yuuki’s chest and is launched at the target; any enemy it hits is mercilessly erased from existence.

Over the course of battle, Yuuki comes into contact with the blood and bodily fluids of the Eight Thunder Gods.

When he absorbs these substances, the defeated gods’ spirits end up residing inside his mind, taking up space in his inner world.

As of the current point in the story, three gods are confirmed to dwell within Yuuki: Soraori, Fushima, and Rairen.

Their presence influences Yuuki’s psyche and may affect his abilities in subtle ways, adding another layer of complexity to his power.

Yuuki’s core desire can be summed up in his declaration:

“If that’s how it is… then I want to become a hero right here!”

This line captures his resolve to protect others, even in a world stacked against him as a man, and foreshadows his growth from confused student into a true frontline hero.

Yuuki’s original concept was very different: early in development, he was planned as a salaryman rather than a high school student.

This was later changed, as revealed by the series’ artist on social media when the manga began.

In the early chapters, Yuuki is notably more focused on the “reward” system, eagerly anticipating Kyouka’s promised rewards for his service.

In chapter 2 he was initially shown with a delighted expression when receiving a reward, but in the collected volume this was edited to a more surprised expression, slightly shifting the tone.

Yuuki’s initial goal was a humorous “become a hero in the Demon Defense Force and get super popular with girls” plan.

However, after joining the Seventh Unit and learning his sister Aoba is alive as a humanoid Shuki, he gains a serious, concrete objective: “Return my sister and the others to normal.”

The emergence of the Eight Thunder Gods and various escalating crises leaves him no time or mental space to dwell on his old “get popular” dream, and it is implied that he simply forgets about it.

Even so, the arrival of unit leaders like Tenka Izumo and other new heroines causes his heart to waver slightly, hinting that his romantic side is still very much alive.