Well, this manga its so... entertaining? i mean the plot are so classic, the protagonist are a studdent, suffers bullyng and he is rescued by his friend, but the plot twist in a random day god apperce in the highschool and transport the principal character tho other world like mmorpg game, with stats and everything, in this world is he betrayed with her friend and the bully expelling him to a dungeon. And the protagonist (Junpei) it strengthens to make the revenge... well, and this is all. The story its classic revenge story, but its rewarding, the protagonist it develops quite well. If you planread the manga take the story chill and you will enjoy it in 3 hours your finish.