A-kun (17) no Sensou

Onodera Goushi is a high-schooler who isn't much noticed in other people's daily life. In a sense, his life feels like it would be the same if he wasn't around. Then one day while returning from school, he finds himself in a life and death situation where a strange girl named Honoka saves him by sending him to another world. He then gets sent to the "Demon Nation" where many non-humans live and where he is able to meet the Ma-Ou (Demon King) who is... an anime otaku?!?! Source: MU