Juushirou is a sickly looking man with long white hair. In volume 18 of the manga, it is revealed that the illness he suffers from is tuberculosis and his hair turned white three days after his illness surfaced. Although his body is weak, he often ingests a considerable amount of food, a classic symptom of tuberculosis. Juushirou's favorite food is umeboshi-chazuke, and there are no foods he dislikes.
Juushirou is respected by many, especially by his subordinates, for his honesty, loyalty, and personal sense of justice. The extent of his honor and respect is such that Yoruichi Shihouin leaves Rukia Kuchiki, Hanataro Yamada, and Ganju Shiba behind when she rescues Ichigo Kurosaki from Byakuya Kuchiki, knowing that Juushirou would not let any harm come to the three. Like Kaien, Juushirou does not give up when he believes something is wrong and will break the rules if he must. He has been close friends with 8th Division captain Shunsui Kyoraku since his youth, and the two frequently work together.
In various Bleach omake chapters, Juushirou is fond of giving people strange or unwanted gifts for no apparent reason, particularily Toshirou Hitsugaya, because "Juushirou" and "Toshirou" sound similar and they both have white hair, making them both Shiro-chan, a nickname meaning "whitey," in reference to their hair). In one sketch, Juushirou gives Hitsugaya a comically oversized stocking full of candy and other treats. In a V-Jump sketch, Hitsugaya is given a life-size figurine of himself in a fighting pose by Juushirou as a birthday present.
Before the demise of Kaien Shiba, Juushirou often left the daily operations of the 13th Division to Kaien because of his illness; this responsibility is now taken care of by his two current 3rd Seat officers, Kiyone Kotetsu and Sentaro Kotsubaki. To Juushirou's chagrin, the two constantly compete over which is the better assistant. Juushirou is the only captain who currently has no lieutenant.
Despite his illness, it is implied that Juushirou is a powerful fighter. He is, along with Kyoraku, considered to be the one of strongest captains beside Yamamoto and Aizen. However, he is limited by his illness to fighting only for short periods of time; excessive action triggers fits of bloody coughing (another classic symptom of tuberculosis). The true extent of his abilities has not been seen in the series; however, he and Kyoraku both held their own against General Yamamoto for a prolonged period, and Yamamoto states that Juushirou and Shunsui, both of whom he trained himself, possess "greater powers on the battlefield than any younger generation, or old."