After being diagnosed with terminal cancer, male student Musashino Takumi is saved by an experimental drug that unexpectedly transforms him into a girl. As he navigates his new life, Takumi discovers that the treatment has left him with an insatiable sex drive and a fully functioning female body. Struggling with his identity and newfound desires, he begins to embrace the pleasures and challenges of womanhood.
With Sogahara hospitalized, Takumi spirals into a life of hedonism and promiscuity, eventually finding herself pregnant. When Sogahara returns with a surprising biological modification, the two reunite in an unconventional romantic bond. Ultimately, Takumi embraces her new life and motherhood, finding peace in her identity as a woman.