Saikasou no Boku ga Dorei wo Kattara: Kankin Kansatsu Nikki

Synopsis

Bullying, neglect... a high school boy in the depth of despair. He commits the heinous crime of kidnapping his crush, Haruka, and holding her in confinement. But that is when he sees Haruka's own twisted nature…! (Source: Comic Killa, translated)