Don: Gokudou Suikoden
Japanese title: ドン 極道水滸伝
Type: OVA
Episodes: 2
Source: Unknown
Genres: Drama
Studios: J.C.Staff
Duration: 50 min per ep
Rating: R+ - Mild Nudity

Takekichi and Masakazu are two tough guys who are forced to go underground when they lose their boss in a turf war in this modern update of the classic Chinese novel "Water Margin".

(Source: The Anime Encyclopedia)