Originally serialized in the yaoi magazine Shousetsu June between December and October , the story was collected into a hardbound novel that was released in Japan in This futuristic tale is set in a world where the Elites are assigned various social classes based on their hair color in the city of Tanagura. Iason Mink, a high-class "Blondie", runs into Riki, a black-haired "Mongrel", and makes him his "Pet", which Riki resents being. As Riki learns of the dangers Iason faces by keeping him, he finds himself developing feelings for his master.
The story is set in the future on the planet named Amoi which is controlled by a supercomputer named Jupiter. Among the mostly male human population, the light-haired elite class is allowed to temporarily keep the dark-haired "mongrels" as pets. One elite member, Iason, encounters a mongrel named Riki in the slums and decides to take him in. However, Iason keeps Riki longer than it is socially approved, and rumors abound about their possible relationship.
One of the central characters in Ai no Kusabi, Iason is the main foil and anti-villain, deuteragonist, and star-crossed lover of the story's protagonist, Riki. Iason Mink was one of the elite aristocrats chosen by Jupiter to be the backbone of Tanagura. He was a new type of man who had risen out of Jupiter's sense of self. For a long time, Iason had lived with a sense of pride and loyalty from the collective will he shared with his creator. Because of this, he had an unwavering conviction that his existence surpassed that of other mortals.