Ren Akiyama, 15 years old. He's a gamer obsessed with the fantasy MMORPG Legends of Arceria. One day, while challenging a supposedly impossible-to-defeat event-only boss, his PC mysteriously explodes -- and when he wakes up, he finds himself in the game world. Up to this point, this is a typical story...or so it seems. However, what he is reincarnated (?) as is not a hero or a warrior, but a "test character" -- an incomplete class used by the developers to test gameplay.