Shimojou can have whatever he wants, but deep down he finds life boring. Constantly searching for a thrill, Shimojou wanders off the path of an elite and descends into life as a yakuza-like lowlife. Nonetheless, he moves forward as if life were an easy game. Then, one day, he comes across a filthy piece of garbage of a man. This is the man, who, during their youth, was the only person who has given Shimojou the taste of defeat: Kuze. The sudden arrival of this fallen Kuze irritates Shimojou.

Trying to ignore his complicated feelings of unhappiness and nostalgia, unexpected words come flying out of Shimojou's mouth. "If you're doing this for money, how about letting me keep you as a pet, then?" An intellectual ersatz yakuza lowlife and a homeless parasitic piece of garbage: their life together begins again, but just where will the future lead them…?