Ja'far is a serious person, who gets angry easily. He is most often the voice of reason when Sinbad is doing something outrageous. He tends to scold Sinbad a lot, despite Sinbad being his King, older, and stronger than him. When provoked or angered, Ja'far shows a whole different side to himself. He was easily willing to kill Cassim when the latter opposed Sinbad. Another time this happened was when Judar called Ja'far a "small fry" and told him to step aside, because he had some business with Sinbad. Enraged, Ja'far was going to use his Household Vessel, Bararaq Sei with his full strength, but was stopped by Sinbad before he could do so. However, despite his short-tempered nature Ja'far is shown to be mostly kind and polite towards others (except for those he sees as an enemy). He cares deeply about the people he loves and is shown to have a soft spot for children, as he treats them almost like a mother. He is also a workaholic, to the point that he would still be working even when he's asleep.