Kiyoko Madoka is a central character in the anime Gilgamesh. She is approximately seventeen years old and was born before the cataclysmic Twin X terrorist attack, an event that fundamentally altered the world and was caused by her father, Terumichi Madoka. Because she was born before this event, Kiyoko does not possess the ability to use Dynamis, a form of psychic power that allows certain individuals to manipulate physical objects and which manifests in those born after the disaster. Her appearance is that of a teenage girl with blue eyes and brown hair worn at chest length.

In terms of personality, Kiyoko is defined by her deep sense of responsibility and her protective nature, particularly towards her younger brother, Tatsuya. She acts as a surrogate mother for him, as their mother fell into a state of depression and alcoholism following Twin X, leaving the siblings largely to fend for themselves. Kiyoko is highly sensitive to sound, possessing perfect pitch, which allows her to match any sound to its corresponding musical note. This ability is tied to her love of music, and she was taught to play the piano by her father when she was very young. A tuning fork, which she finds early in the story, becomes a recurring symbol associated with her.

Kiyoko’s primary motivation throughout the series is to achieve a peaceful and normal life with her brother, free from the shadow of their father’s devastating legacy and the conflict between the opposing factions, Orga and Gilgamesh. However, this peace remains elusive due to the immense debt left by her mother and the ongoing war she and Tatsuya are drawn into. Her role in the story is largely that of an anchor to humanity and a point of contention. While her brother is a powerful Dynamis user whom the mysterious Countess of Werdenberg wants to recruit, Kiyoko has no such powers. This makes her both vulnerable and determined, as she struggles to protect Tatsuya from being manipulated, feeling that the Countess is trying to take him away from her.

Her relationships are central to her development. Her bond with her brother Tatsuya is the most important one, though it becomes strained as he embraces his Dynamis abilities, which she grows to distrust and find repulsive. Her relationship with the Countess is antagonistic; Kiyoko attempts to leave the Countess’s hotel headquarters twice. The first time, she is caught and imprisoned in the hotel’s underground prison as punishment. She is eventually allowed to leave after her second attempt but must work to pay off her debt. After a music shop where she worked as a piano tuner closes, she becomes a hostess in a club in the city’s entertainment district.

Significant development occurs through her relationship with Novem, one of the Gilgamesh. After finding him wounded following a battle, she takes him into her apartment and cares for him, and the two fall in love. This relationship leads to a profound change, as Kiyoko becomes pregnant with his child. This child, who possesses Dynamis, is described as the first of a new, short-lived species. While Kiyoko herself has no supernatural abilities, her perfect pitch and musical talent are her most notable traits, and her compassion and desire for a normal life ultimately lead her to a fate deeply intertwined with the supernatural conflict she sought to escape.