Everyone in a high school is suddenly transported to another world. As they are attacked by monsters they find that some of the students now have superpowers. They organize themselves into two groups: the non-powered Stay Home Group and special powered Exploration Group. On a day where most of the Exploration Group is out, the remaining ones start slaughtering and raping the Stay Home Group.

Majima is an average guy with no abilities who barely escaped death at the hands of his schoolmates. He ends up far away in a cave on the verge of death, exhausted and wounded when a slime monster enters the cave and starts eating away at his hand. It's then that he discovers that he does possess an ability, one that allows him to tame monsters and be their master! With only monsters for allies, will he obtain revenge on his human classmates?