12 Beast, Vol. 1

Three things define second-year high school student Touga Eita: he is hopelessly addicted to video games, he has never kissed a girl, and he will choose saving his own skin over heroics every single time. Even though he is the secret heir to his family's prestigious ninja dojo, Eita has absolutely no interest in the family business and prefers digital bliss. Everything changes when a voluptuous harpy girl named Aero literally crashes through his ceiling. She reveals that she was sent to find him by his missing brother to help save her people, the harpies of the alternate dimension Re-Verse, from an onslaught of giant robotic monsters called Gigas. Eita is dragged into this fantasy world against his will.