Tsukasa Hinomoto is a high school student who learns he was adopted when his parents inform him that his real dad is a prominent company executive. To ensure his son's welfare, Tsukasa's biological father creates an occasion called Marriage Royale, in which eligible Japanese women assemble and compete to marry Tsukasa. The contest occurs on a remote island off Japan, where Tsukasa occupies a manor with the assistance of twin maids, Miku and Miu.