Ren Uesugi and his older sister Mihato flee their abusive father and arrive in the seaside town of Nanami with nothing, until a chance favor to the youngest Kuonji daughter lands them jobs as butler and maid at the family's sprawling mansion. The house is run by the eldest of three sisters, Shinra, a celebrated orchestra conductor helpless at the smallest daily task; the middle sister, Miyu, is a grade-skipping inventor, and the youngest, Yume, an ordinary high schooler. Grateful for steady work and a roof, the siblings settle into a chaotic routine of chores, misunderstandings, and clashing tempers.