Devil virus… When the infected becomes malicious， the virus turns him or her into a monster… Doctor Kitao plots to scatter this virus and rule the world. But a girl stands up to stop this conspiracy… Lethal Angel. She fights against the infected people to stop Doctor Kitao… A new monster， Mosquito Wilzer， appears… This monster suddenly stings Lethal Angel and sucks blood out of her. Mikoto suffers and tries to shake him off but she is losing power… But just then， her partner Lisa appears and saves her. Mikoto transforms into Lethal Angel and defeats Mosquito Wilzer… Doctor Kitao shows himself and Lethal Angel gets angry. But something is happeneing to her right arm! Mikoto’s arm is covered in black light and is moving against her will. Mikoto finds out that she was infected…

Akira Kiyota (Ryusuke Nakamura), an ordinary salesman with poor performance and heavy consumer-loan debt, feels crushed by the harshness of reality—far from his wild days as a former biker gang leader. One night, while entertaining clients at a club, Kiyota loses his temper and punches a customer. The club happens to be protected by his high school classmate Kenji Hosokawa (Sho Ikushima). Kenji knocks out the rampaging Kiyota with an ashtray. When Kiyota wakes up, he finds himself in Kenji’s office. Kenji invites him into his yakuza group, telling him this might be his one chance to turn his life around…

Kiyota Akira (Ryusuke Nakamura) and his former classmate Kenji Hosokawa (Sho Ikushima) begin making money using boat-race betting tricks. Kiyota eventually becomes favored by Yamazaki (Taketarino Yamaguchi) and surpasses Kenji’s results, causing resentment to build within Kenji. Ignoring Kiyota’s warnings, Kenji breaks the strict rules of their boat-race scheme in an attempt to earn big on his own—marking the beginning of his downfall. As his funds dry up, Kenji plans to rob the office of Fujiyoshi (Shinra Manzo), the group’s treasurer. He thinks he can get away with it—but…

Kyowa-kai Himuro and Marukami-kai Tsurumi are in a tense state of conflict. The conflict between the two groups intensified due to internal disputes between the Yokohama and Fujishiro groups. Meanwhile, Himuro's brother Akimoto, a member of the Marukami-kai leadership, dies of illness. With the deterrence of East-West conflict gone, tensions between the Kyowa-kai and the Marukami-kai reach a climax.

Himuro and Tamura of the Kyowa-kai discover that the conflict with the Marukami-kai involving the Yokohama Fujishiro-gumi is a secret maneuver between the Chinatown mafia and the half-grey group Kobura. Having discovered that they have a common enemy, the Kyowa-kai and Marukami-kai formulate a joint strategy, but Himuro and Tsurumi of the Marukami-kai are at odds over the dead Ryuji Munakata.