大奴隷区 君と1億3千万の奴隷

At Ooyashima Gakuin High School, a place known for where its graduates end up, the students of X Class are handed one instruction: fit a device called an SCM inside your mouth. What the SCM does is turn whoever loses to its wearer into that person's slave, and the classroom becomes a market in people, with a hierarchy and a black market running on the same currency. Shinichi Okada and Hiroto Ooishi carry the rules of their earlier Dorei-ku into a far wider arena here.