Yashiro, the ruthlessly efficient leader of the yakuza group Shinsekai, is also a brazen sexual deviant and masochist. Having been hurt by the only person he had ever fallen in love with, he now engages in strictly physical relationships. One day, Yashiro's superior assigns Chikara Doumeki, a recently released prisoner, to the role of Yashiro's new bodyguard. The stoic and observant Doumeki is also clumsy and impotent, much to Yashiro's dismay. Although Yashiro has a personal policy to not get involved with his subordinates, he finds himself strangely drawn to Doumeki, who keeps denying his advances. Despite his refusals, Doumeki finds Yashiro beautiful and wishes to stay by his side, yet he knows that he will never be able to satisfy his boss. As the two grow closer, their complicated pasts slowly begin to reveal themselves. Will their histories get in the way of their emergent feelings?

As Eishin Kuga—nicknamed "Mad Dog" for his unmistakable bloodlust—beats up his underlings, Yashiro watches and waits for his longtime friend to subdue him. Kanji Kageyama, an underground doctor, at last meets the young hothead whom Yashiro wants to recruit for his yakuza group. However, in light of Kuga's aversion toward Yashiro, Kageyama is ultimately left with the chore of temporarily housing him. But as Kageyama continues to insist that he has no interest in men, Kuga's shirtless presence, riotous attitude, and ceaseless teasing might just change his mind.