Jolyne is the main heroine of series 6. She is the daughter of the third arc's hero, Joutarou Kuujou, and is the only female "JoJo" to date.
Quick to anger and snappy with her elders, it seemed like Jolyne was a lost cause. She was irresponsible and flighty, at first only looking to satisfy a cheap thrill. Bitter at Joutarou for leaving the family for so long, she blamed him for her misguided outlook. However, she still had honorable morales and treasured her mother. She would selflessly do everything in her power to help her friends. Jolyne believed that her loved ones had a good heart and an honest nature. Unfortunately, she can believe in them to the point of being gullible as it was through Romeo's lies that she was sentenced to a prison sentence of 15 years.
When Joutarou sacrifices himself for Jolyne's freedom, she noticeably matures and her resolve to "revive" Joutarou turns into her first priority. She adopts more traits like her father and her wardrobe even changes to resemble Joutarou's look. She eventually gains pride for her Joestar bloodline and she becomes rather tough by the end of the series. Her strength and infallible integrity shine in her fights and her willpower soon echoed that of other Jojos.
Her distant and near-fatherless childhood bore a tinge of loneliness in her. Their relationship is challenging at first, not really fitting the typical father-daughter mold. When Jolyne was fourteen, she was wrongfully accused of pickpocketing. Panicked, she stole a car and sloppily tried to make an escape from the authorities, leading to her being arrested and taken into custody. Jolyne anticipated for Joutarou to pay the bail for her but was sorely disappointed when she overheard her mother's frantic and unsuccessful pleas with him on the phone. Her father's absences following this lead to her teenage years of delinquency (she later reflects these events as a desperate call for attention). As time passed, Jolyne came to respect her father more and idolized him somewhat, adapting his trademark "Yare yare daze" into a more feminine "Yare yare dawa." When Joutarou returns later, both father and daughter show considerable care to one another, each in their own way.
Jolyne's mother rarely appears and is hardly talked about. It's assumed that she loves Jolyne very much and dotes on her in Joutarou's absence as she is one of the few people to call Jolyne "JoJo." It's mentioned that she is an Italian-American, making Jolyne 1/4 Japanese, 5/8 Italian, and 1/8 British.
The tattoo on her left arm is a sign of her past membership in a car-stealing gang. It's hinted that she has been arrested before while in the gang, presumably to protect the other members.
Stone Free gives Jolyne the power to unravel herself. Ironically, whenever she moves away from the stand it unravels. At first she is only able to send a string from her fingertip and felt intense pain if it snapped. It also featured the ability to listen to faraway conversations, similar to a can tied to string. Later, she can unravel up to 70 percent of her entire body into a string and quickly reassemble herself. She can also "cut" her string form and make it independent from her body. Jolyne also develops the ability to stitch her wounds together. Like Joutarou, Jolyne also cries, "Ora, Ora!" while pummeling with her fists. Her stand, though perhaps not the strongest, is praised for being both extremely quick and flexible.
Jolyne, unlike her father, is not a naturally awakened stand user. She received her stand when she was cut by an amulet given to her by Joutarou.