Jotaro is canonically established as a tall (195 cm/6'5"), attractive, and well-built man, even as a teenager. He has dark hair that constantly blends with his hat, a strong jaw, bold eyebrows, and green eyes. He also bears a mild resemblance to his great-great-grandfather, Jonathan Joestar, and his grandfather, Joseph Joestar when he was young. Jotaro is introduced as a rough delinquent, but he has a gentle heart and is loyal to those he likes. He is highly perceptive, intelligent, and quick-witted while keeping a perpetually cool, slightly neutral, or disinterested attitudeJotaro's most noticeable trait is his stoic and seemingly aloof nature. He is a quiet individual, often satisfied with expressing himself in short phrases. His bio explains that he thinks anyone can tell his emotions just by looking at him, and probably thinks further effort in portraying how he feels to be a waste of time, making others tend to perceive Jotaro as callous.[7] Related to this, Jotaro is an extremely cool and collected individual, able to keep his composure in even the direst situations.

He is also described to be "the honorable student type",[11] and thus can be described as haughty and somewhat introverted. Though he normally keeps a polite and somewhat formal behavior, Kakyoin is a rather cold and prideful man. In his character bio, Araki describes Kakyoin as effeminate, as he tends to speak in a softer dialect of Japanese and uses feminine diction in the manga. However, he is also noted to also be stern and blunt. He hates bowing down or kissing up to people. The humiliation of having been weak enough to bow to DIO was a part of his motivation for seeking redemption and revenge during Stardust Crusaders.[12] Kakyoin has stated that if he were to ever fall in love, he would want it to be with someone like Holly, because she gives off the feeling that anything will be alright and can calm anyone's hearts, making them feel at ease.[13] Like Avdol, Kakyoin is quite knowledgeable about the nature of Stands. He seems to know more than Polnareff, who was also born a Stand user. For example, he was able to correctly hypothesize that Stands could shrink to a microscopic size. However, his knowledge is much more limited than Avdol's; he didn't know about the existence of colony-type Stands, nor was he aware Stands could turn against their users as with Holly. In a flashback, Kakyoin's mother reveals that he was quiet and disassociated from his peers, turning away anyone who tries to approach him. His own ability to see Stands led to a lonely childhood where he felt nobody could understand him, becoming depressed and cold. However, later in life he proves to be endlessly loyal to those he calls his friends. His reason for joining the Joestar Group is to fight evil, as he mirrors Jotaro's own explanations for saving his life,[13] and a sense of debt towards Jotaro. He thinks only respectable individuals are able to be friends of his. The Joestar Group is the only group with whom he has attached himself, and he cares very strongly for them. Araki himself mentions that if it weren't for their Stands , Kakyoin and Jotaro wouldn't have been friends.[2] Kakyoin has shown to lighten up with Polnareff , although he can also be very brutal and vindictive, having elbowed him in the face as "reconciliation".[14] Appearance Kakyoin is a young man of average to above-average height and fit to slender build. His primary outfit is a proper, trench coat-length, green. Kakyoin keeps his red hair styled fluffed up in the back and longer around the nape of his neck, characterized by a large, twisting bang hanging to the side of his face. Strangely, the side the bang hangs at is inconsistent, changing depending on the way he's facing. He is attractive and has captured the attention of several women. Some of Jotaro's own admirers commented on his appearance, and during the Tower of Gray encounter, he swooned two female stewardesses. He is also referred to as beautiful upon arriving in India by a man trying to sell him a tattoo. Later, Kakyoin acquires two thin scars vertically crossing both eyes, which he often hides with a pair of dark sunglasses. In his character cover for JoJonium, he is seen with shorter, light pink hair and a uniform with a different color scheme than usual, now being black with blue and red details.