Shūga is a very evil and sadistic wolf. He was a smart fighter.
He enjoyed killing and loved his collection of dead canines. He believes that those who are weak shouldn't talk about justice.
Raised to be the Canine Warrior, he was fanatically loyal for his mission and he was unable to deal with the humiliation of losing and saw death as the only option.
Ginga Nagareboshi Gin
When Shūga was still a puppy his mentor Noroi ripped off his paw and sharpened his bone to make his technique Shu Tosso Battouga more effective. Shūga resides in the bamboo forest and has a collection of dead canines, impaled into the bamboo sticks.
He meets up with Gin, Akame, and Kurotora. And challenges Akame to fight him. Taunting him that he will be a excellent addition to his collection. Akame however is stronger and quicker than him, and is soon able to turn the battle in his favor. To prevent the humiliation of losing, Shūga commits suicide by impaling himself into a sharp bamboo stick.
Akame starts to cry after Shūga's death as his obsessive thinking reminded him of his old mission and the ninja dogs of Iga. Akame felt that he and Shūga were too similar. However, Ben tells him that it's not true.