Ai no Kusabi
 Ai no Kusabi takes place on the world of Amoi, which is ruled by a computer named Jupiter. Jupiter has introduced a number of strict social rules to society. Among them, social status is determined by hair color, blonde being the highest, down to black or dark brown as the lowest. The Blondies, genetically engineered by Jupiter, are the highest social class and occupy the capital city of Tanagura. They travel to the satellite pleasure city of Midas, which has an independent slum area called Ceres. Under Jupiter's restrictions, the Blondies are sterile and forbidden from indulging in sexual activities. They keep "pets" (adolescents in their late teens) for about a year, for purely voyeuristic purposes, before discarding them. Further emasculation is seen in the "Furniture", adolescent boys who serve the Blondies. Contrary to popular belief, the hair-color caste system only applies to those working in Tanagura and not in Ceres. The true separation is between those genetically created in a lab (those in Tanagura) and the "mongrels" formed the natural way (those in Ceres). However it was written in the novel that Tanagura manipulated even the natural births of Ceres, ensuring that its population did not grow by restricting the number of female births to 1 in 10. Riki the Dark, a slum mongrel without an ID number, leader of the gang Bison and therefore considered the lowest of the low, one day meets Iason Mink, a Tanagura elite Blondie, the most powerful man in the city and Jupiter's favorite. Iason saves him from being killed by a gang and Riki tries to pay his debt by offering his body to Iason. Instead, Iason makes him his pet and takes him from the slums to live with him. Riki leaves his gang behind without an explanation. Iason keeps Riki, who is bound to Iason with a penis ring, as his pet for three years. This causes a lot of rumors and commotion amongst the other Blondies. Not only is Riki considered too old to be a pet but he is a human mongrel, which is frowned upon. The other Blondies question Iason and his motives, yet Iason refuses to give up Riki whom he has grown very attached to. Iason's friend, Raoul, warns him that Jupiter does not approve of this relationship but Iason refuses to listen. Riki hates his new position, having formerly been a proud leader, and begs Iason for his freedom. Iason grants him a year of freedom and allows him to go back to Ceres, the slums. Riki is welcomed back into Bison and returns to a normal life. He has changed, however, and is unable to forget the time he spent as Iason's pet. When the year passes, Iason decides he wants Riki back. Through his former furniture Katze, who is now a black marketeer, Iason arranges for Kirie, a young member of Bison, to set a trap and catch the gang. This ends with Bison being arrested. Riki is freed and told to return to his master. After Riki returns to Iason, he learns of the taboos Iason has broken to keep him and of how Iason has protected him from the fate of former pets which end up being sold to brothels. Iason even decides to grant Riki a bit of further freedom by allowing him to work with Katze in the black market. Guy, Riki's best friend and former pairing partner from Bison, finds out about Riki's position as Iason's pet and becomes enraged. As a result, Guy decides to get Riki back from Iason. He kidnaps Riki to Dana Bahn. Riki tells Guy that he will never be free of Iason as long as he wears Iason's pet ring. Guy therefore removes Riki's pet ring by giving him a penectomy. Guy contacts Iason and arranges to meet him in Dana Bahn. Iason, thinking Riki is in Dana Bahn because of the tracer in the pet ring, meets Guy there. Iason tries to get Riki back but finds out what Guy has done. After attacking him, Guy sets off bombs that he had planted in Dana Bahn with the intention of killing Iason to set Riki free. Riki appears to stop Iason from killing Guy and get them all out of Dana Bahn. Reluctantly Iason helps Guy and they head towards the exit. As they approach the front gate, an explosion wrecks Dana Bahn. The gates collapse and slice Iason's legs off just above the knee. Riki is forced to leave him there while he takes Guy out of Dana Bahn. Riki sees Katze, who has been waiting outside after Riki contacted him, and tells him to help Guy while he returns to Iason. Iason is surprised to see Riki come back, despite what he had done to him as a pet. Riki sits down next to Iason and offers him a poisonous Black Moon cigarette that Katze had given to him, and they both perish in Dana Bahn together, much to everyone's grief.