Tsukasa the future successor to the Nikaido Company, is a young and talented businessman.

One day, during a party held in Monaco, he was drugged and kidnapped. Upon regained consciousness, he was being auctioned off as a slave.

Naked and bound, Tsukasa has taken the interest of many 'buyers' whose identities were hidden behind the masks.

One particular buyer, the Earl, has bid the highest price and to Tsukasa surprised, the Earl himself in none other the person who used to live in the Nikaido household for ten years?