After quitting the actress job, Riiko lives with Masao, an illustrator. At the same time, Mito, a childhood friend and former idol, moves into Tamaide's house, who works as a studio photographer. Mito plans to give a performance to self-publish her novel about a betta fish. Riiko, Masao, and Tamaide all become involved in Mito's performance event. With the happening of the performance, small changes take place in their lives. A story of one fish, two men, and two women.