Undercover investigator Reiji Kikukawa, nicknamed "The Mole", has infiltrated the Hiura gang led by Masaya Hiura, a.k.a. "Crazy Papillon", and risen to the rank of second-in-command after eliminating the members of the clan who were involved in the illegal drug trade without authorization. A disgraced yakuza member forges an alliance with the Dragon Skulls, a Chinese mafia, to take on the Sukiya-kai clan that is in control of the Kanto Region. Shuho Todoroki, head of the Sukiya-kai, becomes a target and his daughter Karen is kidnapped to be sold at a beauty auction in Hong Kong. Reiji once again tries to do the right thing while remaining undercover as he becomes entangled in a massive international conspiracy. Meanwhile, elite police officer Shinya Kabuto moves to arrest Reiji.