Kouki Yukishiro

Lord of the Flies: Kouki possesses the power of the Lord of the Flies, allowing him to subjugate small living beings to his will by playing the piano. This power enables him to control small creatures with his piano playing. His manipulation primarily focused on insects, with flies being the most notable subjects of his control. Instead of giving verbal commands, Kouki's influence was conveyed through the melodies he played, and the insects instinctively responded to his intentions in any situation, whether attacking his targets or following them elsewhere. The scope of this ability was impressively vast; he could summon an entire swarm of flies across the city of Kamigoe to locate a single person in a distant area.

Pygmy Consciousness: Kouki can see clearly and communicate with tiny creatures known as pygmies or pixies. Thanks to this ability, she has earned their loyalty: they follow her everywhere, protect her when she is in danger, and obey her commands. The pygmies can speak to Kouki; she understands them, and they understand her.

Koki is a talented pianist, able to recognize the pitch of sounds and accurately reproduce musical notes without references. She describes her talent as the ability to visualize sounds.

As a child, Kouki received praise for her piano playing skills, earning her the title of a child prodigy, thanks in part to her synesthesia. However, her passion for the piano began to fade when her mother subjected her to rigorous training that restricted her freedom to play, forcing her to follow the scores precisely. She eventually lost to Aira Shiratori in a junior piano competition, leading her to believe she lacked talent and consequently giving up playing. By the time Kouki reached high school, she found herself ostracized by her classmates and even her own family, as her younger sister, Alice, outshone her in talent.

Koki is a shy and despondent girl. As a child, she took pride in being recognized as a talented pianist. After seeing her moment of glory replaced by a life of isolation among her peers, Koki longed to be recognized again.

Kouki is a slender young woman with long hair that covers almost her entire face and round eyes with large pupils. As a student, she wears the Kami High School uniform: a dark, button-up blazer with the school emblem on the left side of the chest, a collared shirt, a ribbon, long socks, and sandals. Like Rin Sawaki, she wears a long, dark skirt instead of the usual short skirt.

If she ever puts her hair up, it reveals that her eyes are naturally almond-shaped, and that she has rather small eyebrows.

Koki Yukishiro is a 16-17 year old student at Kami High School in class 2-E.