Jonathan Joestar/Personality and Relationships

Personality
"He's not just looks and clothes, but a real honest-to-god gentleman... I like it!"

- Speedwagon

During his childhood, Jonathan was proud and mischievous, yet gentle. Despite already aspiring to be a "true gentleman", Jonathan lacked manners and mostly behaved like a normal child. His mother having died before he could remember her, and his fellow boys ostracizing him because of his status left Jonathan somewhat lonely. While at first, Jonathan didn't have his future strength of will, Dio unwittingly became the catalyst of his growth by pushing him to the edge and humiliating his then girlfriend Erina Pendleton. However, he did have the kindness and courage to immediately jump to Erina's rescue against two bullies bigger than him despite not knowing her.

First and foremost, Jonathan strives to become a "true gentleman." He carries his Joestar name with pride, never betraying the code of conduct he has set for himself and will treat any fellow human with respect unless they prove evil.

Jonathan also possesses a fierce inner strength and the drive to face and overcome conflict, which Dio calls an "explosive power". That drive, fueled by his affection to his friends and loved ones, enabled him to overcome the direst situations, notably managing to save his wife Erina when their boat was overcome with zombies and he was fatally hit in the throat. Jonathan fights for what he believes in, and once he is committed to something, he won't back down until the deed is done. During his journey to find a cure for his father's illness, he was ambushed by a band of misfit hoodlums. He did not so much as flinch as he grasped an assailant's knife within his hand, saying he had much more riding on the fight than merely four fingers.

As a gentleman, Jonathan is also kind and positive. Jonathan has a mindset where he tries to imagine the consequences his actions would have on other people, even if they appear to be enemies. He is gentle and sympathetic, feeling pain even as he vanquishes a zombified copper. Despite his skill in fighting, he will never seriously harm a person without a valid reason. Even after everything Dio has done, Jonathan still considers him his brother, and sheds tears for him. His courteous nature as well as his mental fortitude and ability to withstand fear and pain, is the main reason Speedwagon decides to aid him on his journey. During his life, Jonathan has always had an impulse to save others, beginning with Erina, and ending with his thought of a nearby baby just as he was agonizing from Dio's attack.

Yet Jonathan can feel righteous fury at the evilness of his foes, and will conduct justice by vanquishing them. He admitted that his reason for fighting Dio wasn't out of duty for saving the world, but to avenge his loved ones Dio killed. Moreover, he has no pity for truly despicable individuals he is not familiar with such as Doobie.

With his courage and spirit, Jonathan sets a legacy as the first JoJo of the series.

Fascinated with the Stone Mask, Jonathan tried to study it and even took on the path of archeology. However, not having thought of putting in on anyone, Jonathan didn't discover its true purpose himself.

Family

 * George Joestar I: In his youth, Jonathan's father was very strict on him, correcting his lack of table manners and berating his studies, while ignoring the harm that Dio was bringing on his son. This was perhaps made worse by the fact that Jonathan's mother had died some years ago, hardening George and causing him to be harsher on his son. Regardless, Jonathan still loves his father greatly, angrily beating up Dio, whom he had been friends with for the past seven years, for poisoning his father. When Dio throws a knife at Jonathan, George sacrifices himself to block the knife and comments that "it's not so bad to die in your son's arms".
 * Mary Joestar: Though Jonathan's interactions with his mother are never seen as she is killed while he was still an infant, he is shown to love her greatly, looking at her picture wistfully and crying right after Dio ruins his life with his arrival.
 * Danny: Jonathan and Danny have forged a strong bond since Danny saved Jonathan from drowning in the river. Jonathan is shown to be very angry when Danny was kicked by Dio and had sobbed uncontrollably when the household had buried Danny. Danny still shows up in his master's memories, when Jonathan remembers having fought with Danny over a bone.
 * Erina Pendleton: Jonathan's love interest and eventually his wife first hands him a handkerchief shortly after he is beaten down by bullies. Jonathan professes his love for her afterwards, which she is shown to accept at least in part, until Dio enters and steals her first kiss in order to upset the two. Erina does return after the Joestar mansion burns down, however, and nurses Jonathan back to health, igniting the relationship between the two once more. The two are married after Jonathan manages to defeat Dio with his Ripple, and their relationship continues well into Erina's old age, where her memories of Jonathan prevent her from entering into a relationship with Robert Speedwagon.
 * Giorno Giovanna: Many years after Jonathan's death, DIO uses Jonathan's body to get around in the world now, during which he sires 4 children, one of which is Giorno. Of all the children, Giorno is born first and carries the birthmark thanks to Jonathan's DNA present in his body. While a slightly darker side of Giorno exists, resembling DIO's ruthlessness (albeit towards evil people), he retains a noble heart and desire to help innocents, closer to Jonathan's ideals.

Friends

 * Robert E. O. Speedwagon: Jonathan's most loyal friend. An enemy at first, he later joined Jonathan on his quest after seeing the protagonist's dedication and courteous nature. In his later years, he founded The Speedwagon Foundation, which has become the Joestar Family's most useful asset in battling Stand users and supernatural research.
 * Will Anthonio Zeppeli: Jonathan, upon meeting Zeppeli, was initially perplexed by his appearance and strange abilities. After Zeppeli explains his actions and the significance of the Ripple, Jonathan grows to trust Zeppeli completely and looks up to him as a mentor. Zeppeli eventually sacrifices himself to save Jonathan and transfers his energy and life force to him, moments before dying. Jonathan tearfully avenges Zeppeli by killing Tarkus.JonathanFriends.png
 * Poco: As with the rest of his party, Jonathan felt it necessary to look after Poco during his battle against Dio and his undead army. He takes it upon himself to save Poco's sister during their infiltration of Dio's castle.
 * Tonpetty: Given the short time-sharing, their relationship was nothing more than a cordial respect and empathy with them over the death of Zeppeli.
 * Dire: Dire died too fast to exchange more than a few words with him. However, it is Jonathan who takes revenge on his hands against Dio.
 * Straizo: Given the short time-sharing, their relationship was nothing more than a cordial respect and empathy with them over the death of Zeppeli. However after Jonathan's death, it is Straizo who adopts the child that Jonathan's saves and gives to Erina and eventually teaches the child in the ways of the Ripple. Since Straizo's adoptive daughter married his son that would essentially make them brothers-in-law.

Enemies

 * Dio Brando: In their childhood, Dio and Jonathan do not get along well due to Dio's antagonism towards Jonathan and his ability to both outshine him and ruin his relationships greatly. Years later at Hugh Hudson Academy, Jonathan is shown to have become friendly with Dio, though Jonathan still suspects that something is suspicious about Dio's behavior, while Dio had been plotting to take over the Joestar household. Their antagonism reaches a peak when Dio poisons, and later kills, Jonathan's father and transforms into a vampire. Regardless, both maintain some degree of respect towards one another, as shown when Jonathan suicidally attempts to pin Dio on a pointed statue as the Joestar mansion burned down & destroyed his body in their final battle, and Dio acknowledges Jonathan shortly before attempting to take over Jonathan's body. In the end, Jonathan failed to stop Dio and his body is possessed by him. Their relationship sparks a legacy that continues well into the future parts of the series.
 * Wang Chan: As the man who gave Dio the poison that was used to try and kill his father, Jonathan despised Wang Chan. Unlike Dio, Wang Chan had no respect for Jonathan and constantly insulted him. During his final battle with Dio, Jonathan used the last of his Ripple to kill Wang Chan and use his body to blow up the ship and Dio with it.
 * Tarkus: Jonathan was originally awestruck at Tarkus having learned of him in history books, but after he destroyed the remains of his comrade Bruford, Jonathan lost all respect for him. The two would later battle in a castle chained together and said battle would lead to Zeppeli's death, in anger and sadness Jonathan destroyed Tarkus.
 * Bruford: Like Tarkus, Jonathan highly respected Bruford due to his reputation as a great fighter and knight. After their battle, Bruford also grew to respect Jonathan and gave him his sword before his death.
 * Jack the Ripper: Because he was one of Dio's minions and an infamous serial killer, Jonathan knew Jack was a threat and had to be stopped. In the end, Jonathan destroyed Jack with his Ripple.

Relationships in Eyes of Heaven
(The information below derives from a Video Game not written by Araki. As such, it may not be considered canon.)
 * Giorno Giovanna: When the two are the same team, Giorno will ask Jonathan everything he knows about DIO. If victorious, Giorno will mention that DIO is his father, surprising Jonathan.
 * Jotaro Kujo: At first it was upsetting that Jotaro referred to Jonathan as his ancestor. Later Jonathan felt in his heart that he was succeeding his own lineage, to the point of asking Jotaro to finish Heaven Ascension DIO in his place during the main story's final battle. Also, if Jotaro is Part 4 version, he mentioned to Jonathan's grandson and Jotaro's grandfather Joseph Joestar.
 * Joseph Joestar: Jonathan is impressed by Joseph's tactics and Ripple. He states that Old Joseph reminds him of his father.
 * Kars: Upon encountering him, Jonathan will recognize Kars as the one who created the Stone Masks and seeks to kill him and destroy the Stone Masks. Kars seeks to kill Jonathan simply because he is a Hamon user and later attempts to recruit him to his side, considering his death to be a waste.