An elite Contractor with the Messier Code BK-201. Hei plays a gentle-hearted student from China named Lee Shengshun when undercover. He becomes an apathetic and guiltless killer when on his missions. Joining an organization of unknown ambitions known only as Syndicate, Hei is searching for the whereabouts of his sister Pai, whom he lost several years ago when the South American gate imploded.

A man who is always seen to wear sunglasses and a bartender's suit. Although quiet and nondescript while not angered, he has a very short fuse and fights with incredible strength.He works as a debt collector in Ikebukuro and carries intense animosity towards Izaya. He has a younger brother, Kasuka, who is a top idol under the showbiz name of Hanejima Yuuhei.