Death March kara Hajimaru Isekai Kyousoukyoku

After working himself into exhaustion, programmer Ichirou Suzuki falls asleep and wakes in a fantasy world resembling the games he had been debugging. His body is younger, everyone calls him Satou, and before he can understand the situation he is attacked by an army. A desperate use of an absurdly powerful spell wipes the attackers out and floods him with enough experience to reach level 310 at once.

Satou now possesses the kind of strength that should make adventure effortless, yet he has little interest in becoming a legendary hero. He would rather explore, eat unfamiliar food, learn how this world works, and help the people he meets. Traveling with companions gathered along the way, he treats an impossible second life less like a conquest and more like the longest sightseeing trip imaginable.