A mackerel from the ocean is placed in the fish tank of a seafood restaurant in a Korean fishing village. She is driven to escape after witnessing another mackerel being prepared as food. Her tank is co-inhabited by a group of farm fish consisting of a striped beakfish named Bream, a snapper named Nollaemi, a sleepy sea bass named Bar, a saltwater eel named Jooldom, and the youthful greenling named Spotty. They are ruled by an old flatfish, whom they refer to as "The Master"