Ryota awakens in another world, dropped by a slime that a girl named Emily had killed. Emily is strong, but her drop rates are pathetic, so she does not earn enough to afford a home.

A bunny girl named Eve attacks Ryota, but he survives thanks to his enormous HP stat. Then Eve reveals that the real reason she came to him was because she saw him getting carrots from a dungeon, and she wants some.

Ryota and Emily decide to try out the second level of the dungeon Nihonium for some new drops, but Emily has a problem with the monsters they find there.

Ryota's skill has proven so profitable that he decides it's time to move into a new home with Emily; but then he learns about magic carts, which can help him carry even more items out of dungeons, and sees an opportunity for even greater profits.

A magic storm occurs, nullifying all magic and leaving magic-based adventurers powerless, but Ryota learns of one magic user who is stuck in a dungeon, unable to fight, and volunteers to help her when no one else is willing to take the risk.

Ryota obtains a second gun, which helps him discover a powerful new use for his special bullets. His exploits catch the eye of Secro's dungeon chief, who has a favour to ask of him.