Mc is the only devil child in his village. Demon require to go to at least one year of school. He made a 400 floor dungeon!! He enslaved the vampire king's daughter by accident. He is old friends with the vampire king. Vampire princess is sick and needs medication
16 at ex-demon king's dungeon for training
Jishou! Heibon Mazoku no Eiyuu Life: B-kyuu Mazoku nano ni Cheat Dungeon wo Tsukutteshimatta Kekka