"The Way of the Beast" tells the story of Ai (Sari Ito), a girl born in a city, who was abandoned by her mother who believed in various religious groups and stayed in an orphanage for seven years. She was then arranged to go to a middle school, but she was still not adopted. Ai dropped out of school and was adopted by bad boys and middle-class families at the bottom of society, but she could never settle down. The only one who could understand Ai was the boy who liked Ai, Ryota (Kenta Suga), who was also an orphan and was waiting to be adopted. In the end, Ryota became a thief, and Ai fell into prostitution. Their innocence was swallowed up by the city like a wild jungle. This is a heartbreaking black comedy.