On the planet Amoi, a person's status is primarily dictated by the color of their hair. This society is run by the AI supercomputer known as Jupiter and its governing board of perfect blondes, referred to as Blondies, living in the capital city of Tanagura. However, the darker-haired humans live out their lives in the golden "pleasure city" of Midas and its outlying slum Ceres. They are known as "mongrels," and most cannot progress out of the slums. Three years ago, a boy named Riki disappeared from the slums of Ceres. Once the revered leader of the gang Bison, a sudden encounter with an elite Blondie, Iason Mink, forced Riki to abandon everything he had cultivated. The boy was snatched from his home and forced to become Iason's pet. Riki has spent the past three years enduring numerous blows to his pride, his time in Tanagura nothing but a form of torture. Now that Riki has returned, Bison once again rallies behind him. The risk he finds himself in, however, is much greater than ever before—there is always someone ready to sell him out. [Written by MAL Rewrite]

Young kendo prodigy Ranmaru Samejima captures the attention of Kei Enjoji, the illegitimate son of a yakuza boss. Kei, determined to form a bond with Ranmaru, cultivates a friendship built on trust and sacrifice, which soon turns into love. After saving Kei from a yakuza hit-and-run attack, Ranmaru is forced to give up kendo forever, and the two are left with only their faith in one another. Vowing to support each other far from the world of the yakuza, the two begin living together as a couple. However, when a mysterious figure from the pair's past returns in pursuit of Ranmaru, they are thrust back into the world they fought so hard to leave—and their love may not be strong enough to survive it. [Written by MAL Rewrite]

Yukiya Ayase is a gentle, kind hearted, and innocent university student. The only relative he has left, his cousin Tetsuo, betrays Ayase by selling him to the highest bidder in an auction with hopes of making an enormous profit to be able to pay off his debts. Somuku Kanou, a bad-tempered (though very rich) loan shark, comes to Ayase's rescue and buys Ayase for an impressive 1.2 billion. Kanou apparently knows Ayase from something that happened between them in the past, but Ayase cannot remember who Kanou is nor does he understand why he "saved" him. In a desperate effort to keep Ayase close to him, Kanou demands the debt be repaid in full and suggests the perfect way to do it: by selling his body to Kanou for 500,000 each time. Ayase is horrified in the beginning, but something soon begins to grow between them that can't be bought for any price. (Source: ANN)