Halbert has been reincarnated into the world of a legendary adult RPG. He remembers the game extremely well, but unlike the people who played it for its adult content, Halbert was obsessed with something else entirely: its RPG mechanics. Now that the game's world is real, he has only two goals: become the strongest and completely conquer its dungeons. There's just one problem. The people actually living in this world play by very different rules. If an adventurer's HP reaches zero, they're left helpless before whatever monster defeated them. As a result, everyone considers avoiding damage one of the most fundamental rules of survival. Halbert, however, knows exactly how the game's systems work. To him, HP isn't something precious that must never decrease. It's a resource. He deliberately burns through HP, restores himself with potions, repeatedly hunts bosses, exploits game mechanics, and uses every optimization trick he remembers to gain levels as efficiently as possible. To Halbert, this is just ordinary grinding. To everyone watching him, he is completely insane. His relentless dungeon crawling soon leaves monsters annihilated, supposedly terrifying bosses farmed repeatedly for rewards, and other adventurers wondering what kind of madman willingly fights like this. Along the way, Halbert begins gathering companions who become increasingly swept up in his obsession with efficiency and strength. While the world around him expects the game's infamous adult scenarios to take center stage, Halbert couldn't care less. There are dungeons to clear, items to collect, builds to optimize, and levels to grind.

A reincarnation fantasy about a hardcore RPG player dropped into the world of an adult game who promptly ignores its intended attractions and starts treating his new life like the ultimate dungeon-crawling challenge.