Hiroko Kanzuki is introduced as a shy and soft-spoken girl, and her narrative arc is defined by the severe bullying she endures from her peers. Her personality is initially one of quiet vulnerability, but she carries deep inner turmoil as she wrestles with the psychological toll of ongoing torment, which includes psychological, physical, and sexual abuse at school. This sustained mistreatment becomes the catalyst for her character, pushing her toward a breaking point where she is tempted to use extraordinary power for a terrifying revenge.

As a close friend of the protagonist, Shiina, Hiroko eventually succumbs to the darkness of her own desperation. She uses the psychic link she shares with her Dragon’s Child to slaughter the people around her, demonstrating her shift from victim to perpetrator of horrific violence. Her motivation becomes rooted in a desire to exact retribution on those who harmed her, and this rampage specifically turns toward Shiina’s father, placing her in direct conflict with her former friend. The key relationship in her story is with Shiina, as their bond is tragically severed by Hiroko’s murderous actions. By the end of her narrative, the kind person Shiina once knew is gone, replaced by a malevolent force driven by madness and pain. There is no redemption or recovery for Hiroko; her development ends in death when Shiina’s own Dragon’s Child, acting on Shiina’s desperation, strangles her. Her notable abilities stem entirely from her control over her Dragon’s Child, which she commands to carry out her violent revenge against her abusers and anyone who gets in her way.