Since the Island Academy Incident, silver clansmen Kuroh Yatogami and Neko have been searching for their master, Yashiro Isana, the Silver King. Their search having turned up fruitless, the two begin to give up hope, until they encounter Anna Kushina and Rikio Kamamoto, two members of the red clan HOMRA being chased by someone.—Eleven Arts
Whilst searching for their missing king (Shiro), Kuro and Neko discover Red Clan member Anna Kushina and Shiro are being tracked by the mysterious Green Clan. The Silver and Red Clans team up to protect Shiro and Anna from this new threat.