Tatsuta Ootori

Tatsuta is a second-year student at Kashinokidai High School who deliberately keeps a low profile, blending into the background of everyday school life. During a routine cleaning session, he accidentally uncovered the secret of transfer student Ishikawa Tsukina — that she struggled with blood-sucking and frequently went hungry as a result. He voluntarily offered his own blood for her to practice on. Through the ongoing process of supporting her, a powerful protective instinct awakened within him, eventually making him the dependable "mother-figure" that Tsukina relies on.