When a young traveling chef named Kawase arrives in the frontier town of Kingness, she finds it to be a perfect real-life replica of a town that she used to dream of as a child. Intrigued, she takes a job as a delivery person and occasional chef for a local restaurant. Through exploration and conversations with the locals, Kawase gradually learns the history of the town, the mysterious castle that floats above it, the dangerous cavern that lurks below it and the unspeakable demons who have terrorized its residents.
In Umihara Kawase Fresh!, Kawase carries a fishing lure with "rubber-band action." The lure can be used as a grappling hook to swing from platforms, as a winch to raise or lower herself while suspended, like a bungee cord to slingshot herself in any direction and as a weapon to stun or defeat enemies. The lure can also capture enemies and items in the environment, pulling them in to be stored in the infinite space of Kawase's seemingly magical backpack.