‘Phantom: Requiem For the Phantom’

Adaption of the Nitro+ visual novel Phantom of Inferno. In the American underworld, Mafia leaders are being killed one after another, with rumours of “Inferno” and the organisation’s top assasssin “Phantom” circulating around them. A boy, traveling alone in America becomes involved in one of these incidents and unexpectedly encounters Phantom

Descriptions taken from AniDB.net