Houkago no Dungeon Diver ~Nippon to Isekai wo Ikiki Dekiru You ni Natta Boku wa Level Up ni Isoshimi Masu~

Akira Kudo, a high school student who can freely travel back and forth between Japan and another world, Do Merta. With no goals in mind, he spends his time after school enjoying life in another world as he is! As an adventurer, he gets teased by the guild's receptionist, receives "rewards" from his magic master, and has fun with the girl he helped...!? "I hate pain! I don't care about ranking up! Guild requests are also troublesome!"...