Kurohyo: Ryu ga Gotoku Shinsho
PSP only and Japan-only (never localized). No official translation, port, or Steam achievements.
A handheld spin-off led by a new protagonist, Tatsuya Ukyo, rather than Kiryu. Set in a Kamurocho stand-in, it tells a coming-of-age noir about a street brawler pulled into the underground fighting world.
Combat is modeled on real mixed martial arts, and some cutscenes use live-action footage. As a spin-off, it only loosely ties into the mainline canon.
An early test of whether a Kamurocho drama could work without Kiryu — a distant ancestor of the later new-protagonist lines like Judgment and Ichiban's saga.
This title isn't tracked for Steam achievements. It lives in the archive to help you understand the wider series and its world.