One day, Umidori Tougetsu suddenly receives a mysterious request from Yoshino Nara, a classmate of hers she is rather close with. Little does she know, however, that this is only the beginning of a series of bizarre events. Soon after, an enigmatic girl in a cat hoodie shows up at Umidori's house, calling herself “Bullshit.” Thanks to Bullshit, all manner of strange things happen, including toilet borrowing, betrayal, threats, a grapple for freedom, and finally a desperate plea for mercy. Once everything is over, Bullshit asks: “Hey, will you kill the lies with me?” And without knowing why, Umidori joins Bullshit on her quest.