Game Sekai Tensei <Dankatsu>: Gamer wa [Dungeon Shuukatsu no Susume] wo <Hajime kara> Play Suru

The story centers on a gamer with the player name Zephyrus, who has played the legendary dungeon-crawl game Dungeon Shuukatsu no Susume (Encouragement for Job Hunting in Dungeons or Dan-katsu for short) for over 8,000 hours, but he suddenly loses all his save data and dies of shock. When Zephyrus wakes up, he realizes that he is reincarnated in the unconquered world of the Dan-katsu game. He immediately gets the classic, strongest job as a hero, and starts "a new game" in the world of Dan-katsu. (Source: Anime News Network, edited)