Death March to The Parallel World Rhapsody

Suzuki Ichirou, a 29-year-old programmer, is thrown straight into a fantasy role-playing game. He plays the role of Satou, a 15-year-old in the game. He initially believes he is dreaming, but his experiences appear to be extremely genuine. He ends up wiping out an army of lizard men and becoming a high leveled adventurer due to a great skill he possesses with limited use. Satou decides to keep his level a secret and makes preparations to live quietly and interact with new people. Satou's objectives, however, might be hampered by changes in the game's narrative, such as the reappearance of a demon king.