One day, after defeating a skeleton, a newbie female adventurer, Kurishuna, got bronze sword drop item. When she used her "appraisal" skill to check the sword, the sword absorbed magical power from the surroundings and became Bronze Sword +999 which was clearly much stronger than a legendary weapon.
She wanted to continue being an easy going adventurer after getting the SSS-rank bronze sword, but her surroundings would not allow her. And somehow an orphaned (little) girl from a fallen noble who has come along with her tried to make her become a hero.
Wherever they go, the two of them will create an uproar!