Shinoda Shinjuku Tantei Jimusho Karajishi Botan

The protagonist - Usui Yoshihito works at Shinoda Shinjuku Detective Agency. The agency received a classified assignment from the Shinjuku Central PD. A joint-investigation behind the wide-spread drug smuggling route within Shinjuku area. His partner from the police department, Agumo is a diligent detective. Having a shady past, he feels umcomfortable working with Agumo, but the job itself is right up his alley. Soon, the undercover operation begins. In the meanwihle, he encounters a mafia named Hata, who seems to know Usui's past...