Sawamura Yuki and Katsuragi Tetsuya first met when they were still children. Yuki is the heir to the Sawamura dojo where his family is famous for judo. Soon after Yuki and Tetsuya met, they became good friends and progressed to lovers. Realizing that it’s impossible for two boys to get married, they even made their own wedding testimony. One day when Yuki and Katsuragi were walking and Tetsuya asthma (or some kind of breathing problems) aggravated, Yuki left him with the words "I would not want to die with you" and then ran away.
Tetsuya never saw Yuki since that snowy day, until 12 years later when he became a rich and successful businessman as well as the member of the secret "Kishidou Club" (meaning Knighthood Club). Basically, the purpose of this club is for men to fight each other. Contestants can use whatever type of fighting skills they pocess – from judo to martial arts. Each contestant has an owner and if he loses the match, he’ll have to be punished. The penalty is being publicly molested by other men in the ring. Young and handsome, many (including Tsukasa) would like to be Testuya’s "pony" but he doesn’t take on anyone. When Testsuya found Yuki though, he wanted to torture Yuki for leaving him to die in the snow twelve years ago. So, he offered Yuki a deal. He would pay for all the expenses needed to save Yuki’s invalid father. Yuki couldn’t resist the offer so he accepted the deal and became Tetsuya’s "pony". Of course, aside from fighting in the ring, another part of being the "pony" is to satisy Tetsuya’s psychological and biological desires. This is not easy for Yuki because he knows Tetsuya is not sleeping with him out of love but out of revenge. Day by day, Yuki is constantly being tortured by (a) Tetsuya’s hunger for revenge, (b) Tsukasa’s jealousy, and (c) the tournament which is taking a toll on his knee because of his old injuries. Nevertheless, Yuki made it into the final round – to fight Tsukasa.
The night before though, Tetsuya got a phone call from his friend telling him about Yuki’s old injuries. Tetsuya immediately ordered Yuki not to attend the competition the next day but Yuki still went because he had a feeling Tsukasa (who learned the Sawamura’s school from Tetsuya) could succeed and spread the glory of his own family’s judo techniques. Of course, with such injuries, there’s no way he could beat Tsukasa but he still managed a decent fight. When he was about to be "punished", Tetsuya rushed into the ring and carried him away. Since Tetsuya violated the rules of the club, he should be penalized and this means his business would be in danger. To save Tetsuya, Yuki went to confront the higher ranking members of the club without Tetsuya’s knowledge. However, Tetsuya’s mother saw Yuki and overheard the fact that Yuki was Tetsuya’s pony. She then told Tetsuya the truth.
Twelves years ago, Yuki did not abandon Tetsuya. He rushed to the hospital to call the doctors (and that’s why he got that knee injury). Since everyone was only paying attention to Tetsuya, Yuki’s wound was not properly taken care of and that’s why he could not practice judo anymore in the future. Since Tetsuya’s mother did not want Yuki and Tetsuya to be together, she tricked Yuki that it would be better for Tetsuya to be back in Tokyo as it’s warmer there. That’s why the two got separated. After learning the truth, Tetsuya rushed to save Yuki but he was too ashamed to be with Yuki. So, he left Yuki and went back to the North. His body was fragile and he collapsed but he vanished from the hospital. When Yuki heard of Tetsuya’s disappearance, he had a hunch Tetsuya must have returned to their secret meeting place – a cave in the mountain. So, Yuki went to search for Tetsuya and the two ended up in each other arms, the way it used to be 12 years ago when they were still adolescents.
There are two additional short stories. In the first short story, Tetsuya and Yuki try to become brothers by law (so they can share the same surname), a replacement for marriage. However, Yuki heard from his friends that Tetsuya is getting married and even shopping for rings. So he got very drunk and when Tetsuya came to pick him up, he showed the girl the tattoo on Yuki’s chest (a symbol of their relationship). The girl immediately realize what "kind of" relationship the two really are (of course beyond brotherly affection).
The second short story features Tsukasa. After winning over Yuki, he wants to pursue a career in judo competition but he needs a trainer as it’s inadequate with just the skills he learn from Yuki. So Tsukasa goes to ask the three-time champion and famous trainer Nose Takafumi to be his trainer. However, the guy seems to have lost interest in training people, mainly due to the hospitalization of his old friend. Tsukasa tries many different ways (even sleeping with Nose). In the end, his determination touched Nose and the latter not only saved him from being "nearly raped" but also gave him more than he asked for (and that’s all summarized in the mysterious kiss in the end :P.