Retsuga is a loyal member of the Army Of The Wolf Kingdom and later of the Ōu Army. He is one of the hakkenshi of Sirius and is the Retsu Warrior of them, because he has the ability to use the Retsu Genmu-Battōga. His second ability is to create hurricanes. He's the son of Fūga.
Retsuga is a Hokkaido Wolf with brown fur and white belly. He has blue or orange eyes and a scar crossing his face and the left ear. One of his eyes is missing. He has the typical face markings of his species; stripes around his eyes.
Since the style change, he is seen with silver fur (portrayed blue).
Retsuga is a loyal minion of Reima. He speaks of Reima, Hyōma and Noroi in a respecting way and is always ready to defend them. Been raised so, he is very loyal to the ancient teachings and legends within the wolf clan. However, he later starts to feel suspicious about it and almost loses his respect for them and Reima. Unlike most wolves, he trusts in Gin's powers and believes that he is one of them. He is generally friendlier and calmer than most wolves. He wants to fulfill Hyakkiga's last wish of seeing to outside world and cries when the other wolf dies, proving that he isn't as bad as many other wolves.
Retsuga was born in Reima's Palace. His father Fūga left when he was just a newborn. His mother was a bit later killed by Noroi, when he was still very, very small. Many years passed and he grew believing he never had any parents.
He trained with his master Noroi, learning to use Retsu Genmu-Battōga and to create hurricanes. Later, he goes to find Gin as he turns out to be the user of Zetsu technique. He uses hurricane to kidnap Cross and her pups in order to lure Gin's pack to see his leader. He believes in Gin's strength, believing that he is one of the hakkenshi. Despite being an antagonist of GNG, he explains that Gin is their "kin" and says he won't kill him. He offers to teach Gin how to better use his Battōga, saying that Gin is too inexperienced. Retsuga defends the Palace from the Ōu soldiers and attacks Fūga, not knowing he's his father. Retsuga is confused by Fūga's words but still continues attacking from Noroi's order. Eventually, Suiga ends the fight by telling that Fūga truly is his father and that Noroi killed his mother. This revelation made Retsuga question Noroi and Reima and he joined the Ōu dogs. However, when the misunderstandings are cleared and the true enemy turns out to be Gaia, Retsuga follows his leader to fight the evil wolf lord. After the battle and Reima's death, Retsuga joins Gin's pack along with Hyōma and two other survivor wolves.