For almost a year now, Shiiba has been using Keigo Munechika as his "S," his spy, to get information on the gun dealings of the Yakuza world. Shiiba uses his body in exchange for Munechika's sensitive information...and only his body as far as Shiiba is concerned. Shiiba vows their relationship will not go beyond that. But when a rowdy young man with a penchant for piercing and an enigmatic Yakuza leader cross paths with the young detective, sins of the past are unearthed once more-sins that just might shatter the fragile bond between the detective and his "S."