Mochizuki Yohei is a first year student at National Aleister Academy, he’s one of the rare spirit user capable of summoning a spirit called Geist however his Geist is just a goblin with the worst stat.
One day he stumble upon a walkthrough site explaining that his world is a game called Geist x Revenant and he’s just a mob.
Using said walkthrough, he went on to try to become stronger along with his spirit.