Rairaitei is a small Chinese restaurant run by a grandfather and his grandson, Fujita. One day, as Fujita is about to head out for a delivery, he opens the stacked lunchbox and finds a strange sea otter inside. The otter is remarkably talkative and persuasive, and before long Fujita agrees to let it stay. The creature turns out to be an alien from space, and it has a bottomless appetite and a cheeky personality. What follows is the daily chaos of running the restaurant while coping with the otter’s gluttony, mischief, and unexpected charm. The story traces Fujita and the otter’s odd coexistence, from the initial shock of the otter’s arrival through a series of comedic episodes, and eventually leads to a heartfelt conclusion that mixes laughter with farewell.