AI No Kusabi

Ai no Kusabi (間の楔?) is a Japanese novel written by Rieko Yoshihara. Originally serialized in the yaoi magazine Shousetsu June between December 1986 and October 1987, the story was collected into a hardbound novel that was released in Japan in 1990. 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. Focusing on the relationship between Iason and Riki, Ai no Kusabi also explores issues of caste systems and social exclusion.

The novel was partially adapted into a two-episode original video animation (OVA) by Anime International Company (AIC), with the first episode released in August 1992 and the second in May 1994. In November 1993, an audio drama entitled Erogenous Dark was released focusing on a time period left unexplored in the original novels. A new thirteen episode OVA adaptation, also from AIC, was scheduled to begin releasing in Japan in the spring of 2010, but was cancelled for financial reasons. The project was picked up again and is scheduled to release in January 2012.

The novel is licensed for an English language release in North America by Digital Manga Publishing which published the novel over an eight volume series, with the first released in November 2007 and the sixth in July 2009, with the final volumes scheduled for release in summer and winter of 2012, respectively.