Yuka is an employee at a major Japanese trading company who finds herself dumped by her elitist boyfriend, also a colleague. To make matters worse, she ends up getting demoted and is transferred to a soon-to-be-closed aquarium that's affiliated with her company. Yuka's former boss and ex-boyfriend from the head office come to the aquarium with intentions of closing it, arousing suspicions in Yuka's trainer, Kaji. As a result, Kaji pushes Yuka harder and harder in her work as a dolphin trainer. But over time, Yuka sees through his harsh exterior and recognizes he has a deep love for the aquarium's animals. She becomes competent at her job through the relationship with her dolphin, while beginning to develop feelings for Kaji. Yuka's personal and professional lives are now poised to emerge from the depths!