Boukensha Guild ga Juunisai kara Shika Hairenakatta no de, Sabayomi mashita.

Kiri, a nine-year-old boy, left his countryside home by himself to make a living.

Betrayed by an adult he trusted, he is nearly sold to slave traders. However, he manages to escape and finds his way to the Adventurer's Guild, a tavern called "The Raging Kelpie's Fin."

In order to become an adventurer, Kiri lies about his age, claiming to be twelve. He overcomes numerous hardships and forges deep bonds with his eccentric and quirky companions.

This is the story of a boy's growth into a full-fledged adventurer!