A young Dutch woman, Rosa, comes to Japan to learn the art of preparing fish from Master Kon, the best fish-chef in the world. Against her expectation Rosa has to work in the cleaning-kitchen, together with other unpaid novices. Here begins her lonely journey through the alien and hierarchic world of the famous fish restaurant.
After a while Rosa gets into financial problems and she has to take a job on the side. She becomes a hostess in a night club. Her isolation grows and she discovers that working in the club is like being in an 'aquarium' herself.
The tempting and delicious fishes from Master Kon, as well as his supreme mastership - he catches fish out of the water by hand - make her stay. But to reveal his secret, Rosa has to descend into her own underworld. When night and day meld and it all comes together, she learns to understand the fishes and to become like the master.