Aoi Hitsuji no Yume Blue Sheep's Reverie

Synopsis

In order to find out the criminal who killed his lover, Kai shows up in the town that the two groups, Saruto and Maina, are ruling. There he manages to get close and become the bodyguard of "Steel Ratri," a man who has the same ring as Kai's lover, on his hands, but… (Source: Countless Time)