Retsuga is a Japanese Wolf, son of Fuuga and one of the Eight Canine Warriors of Sirius. Reima's loyal minion, trained by Noroi, he can create hurricanes.

Born in Reima's palace, Retsuga's father left and his mother was shortly after killed by Noroi, without Retsuga knowing, thinking to have no parents. He was sent to kidnap Cross and her pups to lure Gin to Reima and he defends the palace from the Ohu soldiers and from Fuuga, which he tried to kill, not knowing that he was facing his father. Suiga stops them, revealing that Fuuga is his father and that Noroi killed his mother. Retsuga questions both Noroi and Reima and joins Ohu. In the end, he sides with Reima in the fight against Gaia wolves.

After the battle, Retsuga decides to join Gin and his army and moves to Ohu. It is unknown if he's alive or deceased.

In first edition manga there colored spine where Retsuga is brown, but in colored images later manga editions, his colours changed to greyish-blue.