Ryuko Matoi

Ryuko backs down from no one, openly challenging authority figures like Satsuki Kiryuin, her older sister, without hesitation, being stubborn and fearless.

She tends to rush into fights headfirst without a plan, driven by intense emotions rather than cool calculation, being hot-headed and impulsive.

She is initially deeply embarrassed by Senketsu's revealing transformation form, but she quickly overcomes her shyness to focus on the fight.

Though she views herself as an independent outsider at first, she deeply cares for her friends and will risk her life to protect them.

Despite her tough, aggressive exterior and initial quest for pure revenge, she acts out of a genuine desire to do what is right rather than a love for violence.

Ryuko is a woman of medium height. She has blue-black hair of medium length with a single left-swept red highlight on her bangs as well as blue eyes, which have peculiar gear-like pupils with eight grooves around the edges. She has a voluptuous body. She is 21 years old. She started wearing a white collared shirt with a red bow tie which is worn under a black & white varsity jacket with rolled-up sleeves, as well as a black skirt and white sneakers. During her childhood, she wore a red collared shirt with a white skirt and white shoes.

Baring her shoes, she's now wearing Senketsu, a living navy blue sailor uniform. Her shirt (Senketsu's upper jaw) is a dark navy sailor uniform with mid-length sleeves that bares her midriff. The collar has red stripes and is tied by a multicolored scarf that also serves as Senketsu's left eye. His right eye is covered by a black "eyepatch" with an X-shaped mark over it (perhaps emulating her father's right eyepatch). Her skirt (Senketsu's lower jaw) is held up by suspenders attached to a belt. She's later provided with a Seki Tekko, a red, fingerless, left-handed glove with a built-in syringe designed for Ryuko to conveniently draw blood and feed it to Senketsu.

Ryuko's appearance changes further when using Life Fiber Synchronize with Senketsu. Her hair becomes even more feathery and is accented with vibrant red undertones and horn-like clips. Senketsu himself also undergoes a significant change in appearance after Synchronization; his "eyes" extend into wing-shaped crests jutting out from Ryuko's shoulders and his upper and lower parts transform into a black, skimpy suit of armor with red stripes. The top section of the armor covers Ryuko's neck, lower-jaw, arms, and upper breasts, and possesses a red, triangular ventilation grill centered on Ryuko's upper back. The top armor piece is connected to her skirt by three red garter belt/suspenders (two in front, one in back), leaving everything between the underside of her breasts and her waist exposed. Her legs are covered with thigh-high boots with heels.

Senketsu is a composed and analytical individual Kamui, calmly observing and assessing situations as they occur. He maintains this level-headedness even in the heat of battle, thinking of attack strategies, giving Ryuko advice and warning her whenever she is about to run out of energy. He initially shows a manic and aggressive craving for Ryuko's blood, as he needs it to remain active, although this is satiated once she starts wearing him regularly.

Despite being an article of clothing, Senketsu is shown to have undeniably humanistic qualities, such as genuine and even fatherly love of Ryuko, crying when getting sentimental and feeling lonely whenever Ryuko is not wearing him, which is accentuated by the fact that only she can hear his voice.

Senketsu is horrified of being washed by hand, as it is quite painful for him. However, he is fond of being ironed, which he finds soothing.

Senketsu appears to be a navy-blue and red sailor suit with the midriff shown and a lower-cut skirt. When Senketsu is on his own, the section between the shirt and skirt resembles a mouth, in that he is attached to his lower jaw at the back. When he is worn, however, the skirt is connected to the upper body by three suspenders. He speaks to Ryuko with a deep male voice and everyone refers to him with male pronouns, even though Kamui are technically agender entities.