Mitsuko is a central figure in the story of Suicide Club, appearing as a high school student whose real name is Yoko Suzuki. The name Mitsuko is not her original identity but a title that is passed from one girl to another. It was first held by Keiko Ota, who led a similar suicide circle at her middle school and died in a group suicide attempt from which only Yoko survived. After transferring to a new school, Yoko adopted the name Mitsuko and continued the legacy. She possesses an eerie demeanor that naturally draws other girls to her, and she refers to these followers as her children. She encourages them to self-harm as a way of expressing their feelings, and eventually proposes a mass suicide as the culmination of their shared experience. For Saya, the sole survivor of the initial mass suicide, Mitsuko is a close friend and mentor. Saya is devastated when Mitsuko dies in that first incident while she herself survives. Mitsuko’s motivations are rooted in her own traumatic past and her belief in the necessity of disconnecting from oneself, a philosophy she imparts to her followers. She is the catalyst for the chain of suicides that follows, her influence persisting even after her death. Her notable ability is her charismatic and almost hypnotic presence, which allows her to gather and lead vulnerable girls toward self-destruction. In the aftermath, the title of Mitsuko can be taken up by another survivor, perpetuating the cycle.