Ryūko Matoi is a 17-year-old girl of medium height with blue-black hair, accented by a distinctive red highlight sweeping across her bangs, and blue eyes featuring gear-like pupils with eight grooves around their edges. Her initial attire consists of a white collared shirt with a red bow tie, worn beneath a black-and-white varsity jacket with rolled sleeves, paired with a black skirt and white sneakers. As a child, she wore a red collared shirt, a white skirt, and white shoes.

From Episode 1 through Episode 24, Ryūko’s outfit is replaced by Senketsu, a sentient navy blue sailor uniform. Senketsu’s design features a cropped, midriff-baring top with red-striped trim, mid-length sleeves, and a multicolored scarf that doubles as his left eye. His right eye is concealed by a black eyepatch marked with an X, mirroring Isshin Matoi’s eyepatch. The skirt is supported by suspenders attached to a belt. To maintain Senketsu, Aikurō Mikisugi provides Ryūko with a Seki Tekkō (赤手甲, Red Gauntlet), a fingerless glove with a built-in syringe that allows her to feed Senketsu her blood.

When activating Life Fiber Synchronize with Senketsu, Ryūko’s appearance undergoes dramatic changes. Her hair becomes feathery with vivid red undertones, sometimes styled with horn-like clips, while Senketsu transforms into an armored, revealing battle form. In this state, Senketsu’s “eyes” extend into wing-like crests on her shoulders, and the outfit takes the form of a black, skimpy suit with red stripes. The upper piece covers her neck, lower jaw, arms, and chest, while three red suspenders connect it to the skirt, leaving her midsection exposed. Her legs are clad in thigh-high, heeled boots.

Ryūko later achieves Senketsu Kisaragi, Senketsu’s final form, in which his eyepatch shatters to reveal a hidden eye. The uniform’s color scheme changes to reddish-orange and yellow, with elaborate headpieces resembling rabbit-like ears and energy bands forming a jaw-shaped skirt. In this form, Ryūko’s hair turns blonde, completing her transformation.

Ryūko Matoi is characterized by her fiery, stubborn nature and willingness to challenge authority. She displays little fear, confronting Satsuki Kiryūin directly and demanding answers, and shows determination even when facing opponents far stronger than herself. Despite this boldness, she initially struggles with embarrassment over Senketsu’s revealing combat form, though she eventually overcomes her self-consciousness and embraces their partnership.

Once accustomed to Senketsu, Ryūko grows more confident and resourceful, often relying on unconventional tactics in her battles against the Elite Four. However, her confidence occasionally leads to misjudgments, such as underestimating Uzu Sanageyama after his self-imposed blindness.

Beneath her fierce exterior, Ryūko is capable of warmth and vulnerability. She finds comfort and a sense of belonging with the Mankanshoku family, appreciating their hospitality and family dinners, experiences absent from her own childhood due to the early loss of her mother and her father’s distant upbringing. She shows flashes of politeness and restraint, often choosing not to harm those weaker than herself, as demonstrated when she spares Mataro and his gang in their first encounter.

Her determination is most evident in her quest to avenge Isshin Matoi, culminating in extreme resilience, such as breaking free from Ragyō’s mind control by sheer force of will. However, she is not immune to emotional turmoil. When confronted with the revelation of her parentage and Ragyō’s brutal actions against Satsuki, Ryūko briefly falters in shock and despair.

During her forced union with Junketsu, Ryūko’s personality shifts dramatically, becoming violent and sadistic under Ragyō’s control. After being freed, she regains her composure, emerging calmer and more mature. She eventually reconciles with Satsuki, recognizing her not only as an ally but also as her sister, symbolized in her final acknowledgment by calling Satsuki “sis.”

Ryūko Matoi’s mother was long believed to have died shortly after her birth, and her relationship with her father, Isshin Matoi, was distant. With Isshin preoccupied by his research, Ryūko spent much of her childhood in the dormitories of Ox Elementary School. Lacking parental guidance and frequently targeted by bullies, she grew into a delinquent, often fighting and eventually joining a gang.

Six months before transferring to Honnōji Academy, Ryūko received a message from Isshin and returned home, only to find him mortally wounded with a red Scissor Blade lodged in his chest. With his final words, Isshin told her that if she wished for peace, she should walk away, but if she wanted to fight in his stead, she should take the Scissor Blade. He assured her that as long as she possessed the weapon, she would uncover the identity of his killer.

Before Isshin could explain further, Ryūko glimpsed a shadowy female figure wielding the other half of the Scissor Blade fleeing the scene. She gave chase but failed to capture the assailant. Moments later, an explosion consumed the house, leaving her no chance to save her father. Traumatized and furious, Ryūko swore vengeance and began wandering in search of her father’s murderer, a pursuit that eventually led her to Honnōji Academy.

Natural Abilities

Superhuman Strength
Ryūko demonstrates strength far beyond that of an ordinary human. Even without Senketsu, she was capable of defeating multiple One-Star students at Honnōji Academy, as shown in her first appearance. Over the course of the series, her physical power continued to grow, both independently and through synchronization with Senketsu. In one instance, while wearing only a scarf containing Senketsu’s eye, she defeated numerous students clad in upgraded Goku Uniforms while riding a motorcycle. Her strength increases further after she accepts her nature as a Life Fiber hybrid, allowing her to shatter COVERS and free their victims with a single strike of the Scissor Blade, and even slice through buildings with one swing.

Superhuman Regeneration
Ryūko’s Life Fiber-infused body grants her extraordinary regenerative capabilities. She can survive and recover from otherwise fatal injuries, such as her heart being ripped out by Ragyō Kiryūin, which reattached itself automatically, or when her body was severed in half, after which she regenerated almost instantly. By the climax of the series, her recovery rate had accelerated to near-instantaneous healing.

Life Fiber Infusion
Ryūko is revealed to be the second child of Ragyō Kiryūin, whose body was infused with Life Fibers shortly after birth. Though the experiment was initially deemed a failure, it later became clear that her unique physiology allowed her exceptional potential, particularly her innate ability to synchronize with Life Fibers.

Senketsu
At first, Ryūko was reluctant to wear Senketsu due to his revealing transformation, but she later accepted that embracing him openly was the key to unlocking his power. She came to regard Senketsu as a close friend and partner, stating that anyone who tried to take him away would have to pry him from her “cold, dead fingers.” Their bond deepened over time, especially after she overcame her identity crisis as a Life Fiber hybrid.

Mako Mankanshoku
Ryūko quickly formed a strong friendship with Mako after enrolling at Honnōji Academy. Initially overwhelmed by Mako’s energy and attachment, Ryūko grew to rely on her as a source of emotional support. Mako consistently encouraged Ryūko during battles and was described by Senketsu as the one who helped her relax. Their relationship culminates in Mako asking Ryūko on a date before the final battle, a promise that motivates her to keep fighting.

Aikurō Mikisugi
Although Ryūko remains wary of Aikurō, he frequently aids her in uncovering the truth behind her father’s death and watches over her battles from the shadows. His tendency to flaunt his physique often embarrasses Ryūko, but he proves his loyalty by hesitating to harm her, even when others, such as Tsumugu Kinagase, consider it necessary.

Satsuki Kiryūin
Ryūko and Satsuki begin as bitter rivals, with Ryūko resenting Satsuki’s secrecy regarding Isshin’s murder. Over time, their relationship evolves, particularly after Satsuki reveals her coup against Ragyō and her grief for her supposedly lost sister. When Ryūko learns that she is Satsuki’s younger sibling, their bond solidifies, and the two fight alongside one another to defeat Ragyō. By the series’ conclusion, they accept each other fully as sisters.

Uzu Sanageyama
Ryūko and Sanageyama’s rivalry stems from her victories over clubs under his command. Confident in his Tengantsu, Sanageyama openly challenged her, only to be humiliated in defeat. After sewing his eyes shut to enhance his abilities, he sought revenge but failed to secure victory. Despite this, he came to respect Ryūko, referring to her as the one who “took his eyes and gave him the world.”

Nui Harime
Ryūko harbors deep hatred for Nui, who killed her father. Their encounters often drive Ryūko into uncontrollable rage, leading to Senketsu’s berserk state. Over time, however, her feelings toward Nui shift from hatred to disdain, frustrating Nui, who thrived on being the object of Ryūko’s animosity. During their final battle, Ryūko dismembers Nui and absorbs her Life Fibers, breaking her cutesy facade and forcing her to confront defeat.

Ragyō Kiryūin
Ryūko’s relationship with her mother is marked by rage and betrayal. Upon learning that Ragyō had experimented on her as a baby, Ryūko’s disdain turned into hatred. Though she fought her mother with the intent to stop her, Ryūko still offered Ragyō a chance to surrender peacefully after her defeat. Ragyō instead chose suicide, ripping out her own heart rather than returning to Earth.

Junketsu
Forced to wear Satsuki’s Kamui during Ragyō’s trap, Ryūko lost control of herself, becoming violent and bloodthirsty under Junketsu’s influence. Her enhanced power and savagery turned her against her allies until she eventually broke free. Disgusted by the experience, Ryūko forcibly tore off Junketsu, rejecting him entirely.