Alba Thomas, an S-rank gatherer who travels across the land in search of precious items such as dragon horns and golem cores, one day discovers a school-bag-wearing girl inside a treasure chest. The girl, who calls herself Nono, is still young and doesn't know where she came from. And to complicate matters, under the kingdom's rules Alba and Nono are no longer able to leave the dungeon. Unable to simply leave her in such a dangerous place, Alba decides to take Nono under his protection. However, meals prove to be a struggle: while Alba can easily procure ingredients, he is utterly inexperienced when it comes to cooking. Stepping in to help is Nono, who displays genuine talent in the kitchen.