A boy named Mars Luina, who had no goals and spent his days in idleness, saves a woman named Lania who was being attacked by a monster.

Witnessing Mars's skill, having defeated the monster in an instant, Lania asks if he's a famous adventurer belonging to some adventurer's guild. However, the truth is, this boy Mars was merely unemployed.

Consequently, Lania, an instructor at an adventurer training institution, invites Mars to consider aiming to become an adventurer...

※Published as a 4-volume book series by KADOKAWA BOOKS.

Volumes 1 and 2 have undergone significant revisions, while volumes 3 and 4 are entirely new material.