Hikigaya Hachiman, shortly after an odd Valentine's day, finds himself in a new world filled with magic, monsters, and gods. Though he knows not how he got there, he knows that the only way back to his home is through the Dungeon. Armed with a few tricks, a wholly unnatural affinity for magic, and his own, self-serving mindset, he just might manage to achieve his goal. Well, if he ever manages to get a party.