Taro stops being a passenger in his own life the moment he walks into that mansion. The ecchi setup dissolves into actual character work, hundreds of maids who feel like people instead of designs, each one pulling the narrative in unexpected directions. By the time the Mariel romance lands, you've watched a show about loneliness and inherited responsibility become something that actually means something.
After his mother dies, middle schooler Taro Hanaukyo goes to live with his grandfather in Tokyo and is stunned by the enormous mansion waiting for him. His grandfather, Hokusai, head of the wealthy Hanaukyo family, has no heir and has retired to a remote island, so Taro becomes master of the estate and head of a family that controls half of Japan. The house comes with hundreds of maids ready to serve him around the clock. Leading them is Mariel, the chief maid, joined by specialists such as Tsurugi Konoe in security, Ikuyo Suzuki in arts and Grace in computers. Together these skilled professionals form the Hanaukyo Maid Squad, devoted solely to serving Taro. The result is a comedy with romance and plenty of ecchi fanservice.