Two men, a detective and a gang member, infiltrate each other's organization. Soon they find their fates intertwined.

This is the continuation and final part of Double Face SP, the Japanese remake of the highly successful 2002 Hong Kong film, Infernal Affairs. This special focuses on Police Inspector Takayama Ryosuke (Kagawa Teruyuki) who had been secretly supplying police information to the organized crime group, the Oda-gumi. Once a young street thug, Takayama was taken under the wing of Oda Hironari (Kohinata Fumiyo), the leader of Oda-gumi. Dressed, fed, and educated, Takayama was instructed to become a police officer and work as a mole for the group. Now, he is tasked to get close to Suenaga Mari (Aoi Yu), a daughter of an influential politician.