Ganju Shiba

is an outrageous figure. He wears a vest, scarf, bandana, and pair of goggles. He is often found with his gang, who all ride large boars. Ganju's boar is named Bonnie (affectionately referred to as Bonnie-chan) and is tattooed with kanji lettering on the side which roughly translates to "four-wheeled drive". The omake sketch after episode 114 implies that Bonnie was accidentally cooked into a stew by Retsu Unohana during a friendly cookout including her, Ganju, and a few others from the 4th Division. Similar sketches have occurred in the series, but Bonnie is always shown alive and well by the next episode. Ganju possesses a deep hatred for shinigami, a hot temper, and a strong ego. Though he always acts tough, he has shown that he also has a softer side, easily being cowed by his older sister Kūkaku, and later develops an understanding to Ichigo Kurosaki with a relationship similar to Ichigo and Renji Abarai's. The fact that he is not particularly attractive is a running joke in the series, and rather than deny this fact he tends to talk around the subject, especially when Yumichika Ayasegawa makes note of it.

Because of his brother's, Kaien Shiba, death at the hands of Rukia Kuchiki when he was still young, Ganju holds a grudge against all shinigami. This grudge is slow to dissipate even after he learns the truth of the incident. It is implied that after Kaien and his wife Miyako's death, the Shiba clan lost its status as one of the Noble Clans (which include the Kuchiki and Shihouin clans). There now remain only four Noble Clans, as the Shiba had been the fifth. Upon Ganju's introduction, he and Kūkaku are the only remaining members of the clan.

Though Ganju is not a member of the shinigami forces, he is of the Shiba clan and can fight on a level above that of an average shinigami, but lower than that of the higher ranking seated officers. He has a zanpakutō which resembles a meat cleaver or a Chinese Dadao, though he never demonstrates the ability to use its initial release. Ganju's sword skills are limited, so he relies primarily on his arsenal of fireworks, his agility, and his earth magic. Ganju's earth magic doesn't seem to operate on the same principal as standard shinigami kidō. The one technique he uses, Stone Wave (石波, seppa), doesn't need an incantation to work and is unnumbered. The spell can reduce whatever it is aimed at to sand or quicksand. He can even perform it with his feet. This ability proved to be useful to make holes through the walls when running away from Yumichika.