The Boy with the Koi Tattoo is the second novel in the Boys in Love Series. It starts immediately where the last book finished and now Dai Uie is wandering the streets alone when he stumbles into Kabukicho, a well known red-light district in Tokyo and is confronted with a gang of Yakuza thugs who drag him into "The Red Building" an infamous gay brothel in 2-chrome.

Dai soon meets Shi, the beautiful and mysterious 19 year old Adonis of the place and the two form a near unbreakable bond; trapped in an inescapable fate Dai's new love carries the weight of a dark past and deadly ambitions.

With the emergence of the latest drug "CHi", a destructive motorcycle gang called the "Grim Riders" led by the wild and terrifying Miki, a jealous lover, and a brewing war between the street gangs with the Yakuza thrown into the mix makes life and love difficult to grasp.