Messed Up Disturbing Manga

Trigger Warning death, mass murder, exploitation of minors

Hasumi Seiji, who teaches English at a high school, is affectionately known as "Hasumin" by his students. He's popular, good-looking, kind to everyone, and efficient at teaching and solving problems. But no one knows that he's actually a manipulative serial murderer. He treats the school as a kingdom he rules. He manipulates others into trusting him and obeying him.

Who do you think lives next door?
A college student?
A secretary?
A foodie?
A quiet sort?
Or... A killer?
This is the birth of a brand-new suspense horror masterpiece!

Trigger Warning rape, sexual assault, disturbing images, murder, torture

Eyama Aito, a high school student, is the victim of daily bullying. One day a strange letter arrives inviting him to a "captivity game." He may choose one person to hold captive for one month with a chance at winning a large amount of money. He chooses the ringleader of his bullies, Aya Kirishima, and the only rule of the game is to not kill her. Everything else is fair game. Eyama's revenge begins!