異世界で魔王を倒して日本に帰ってきたら、地上にダンジョンが出現しました (Associated Names)

Andou Shougo, a normal high school student you can find anywhere, had one day died after a falling meteorite hit and destroyed his skull. When he came to, he was in a completely white world. There, he met a girl claiming herself to be God, ordering him to go and defeat a Demon Lord in…