Ginga Densetsu Weed: Orion (Silver Fang Legend Weed: Orion) was first published July 24, 2009 and is the continuation of the adventures of the Ouu army. The story is centered around Weed's children — Sirius, Orion, Rigel, and Bellatrix — and several other children of Ouu's veterans. New characters have been introduced such as Kurohabaki Masamune, the main antagonist and leader of the notorious Kurohabaki Clan.
The series follows Weed's offspring: Bellatrix, Rigel, Sirius, and in particular, Orion.
An earthquake and subsequent volcanic eruption separates Orion from his parents and siblings. With the Ōu Mountains in complete disarray, new threats arrive to exploit its weaknesses. Three sons of the Irish Wolfhound Kamakiri, a platoon leader for Hōgen, wish to avenge their father's death.
Meanwhile, Kurohabaki Masamune, the leader of the Kurohabaki Clan of ninja dogs, aims to take over Ōu, gathering recruits and killing those who resist.