"Wanna be my Sidekick!?" She asked while grinning ear to ear. A Demon girl who lives amongst the humans and is trying to be one of the greatest demon heroes in the underworld while she attends high school and tries to live amongst the humans. That demon girl's name is Marilyn, and she aspires to be the greatest demon hero in the underworld, but such a task can't be done by one person. She's learn from the greatest in the underworld that to be at the top, you need a sick kick. She doesn't just want any random person. She's had her eye on someone. A classmate of hers, she feels that he's a perfect fit to be her sidekick. His name is Oliver Rojas, and he is oblivious of what is going to go down on the first day of high school. Care to find out what happens in Half Demon, Even Demons can Be Heroes!?