SPOILER WARNING: Part 1-8 spoiler details may follow.
“
The youth of this town have a golden spirit. The same golden spirit shining with justice we saw on our journey to Egypt. That spirit they embody will naturally course into others without a word...
The Joestar Group is a nickname given to the team of protagonists prominent in each part of JoJo's Bizarre Adventure. The group is composed of different members in each part, but generally consists of a JoJo and various other allies all following the same or a similar plan of action (i.e defeating DIO or protecting Morioh).
★: The character is leader (✩: Subsequent leader / ✦: Leader of their own faction within the group) (👻: The character remains as a soul or ghost)
☮: The character has resigned
⚓: The character retired (incapacitated) and/or their fate is unknown
★: The character is leader (✩: Subsequent leader / ✦: Leader of their own faction within the group) (👻: The character remains as a soul or ghost)
☮: The character has resigned
⚓: The character retired (incapacitated) and/or their fate is unknown
Stardust Crusaders
48 years later, in 1987, Jotaro Kujo, the grandson of Joseph Joestar, learns that DIO has returned from the bottom of the ocean. Jotaro, who has now acquired a Stand called Star Platinum, journeys to Egypt to defeat DIO and release his mother Holy from DIO's curse, with help from his grandfather Joseph, Muhammad Avdol, Noriaki Kakyoin, Jean Pierre Polnareff and a dog named Iggy.
★: The character is leader (✩: Subsequent leader / ✦: Leader of their own faction within the group) (👻: The character remains as a soul or ghost)
☮: The character has resigned
⚓: The character retired (incapacitated) and/or their fate is unknown
★: The character is leader (✩: Subsequent leader / ✦: Leader of their own faction within the group) (👻: The character remains as a soul or ghost)
☮: The character has resigned
⚓: The character retired (incapacitated) and/or their fate is unknown
Vento Aureo
2 years later, in 2001, Giorno Giovanna, the son of DIO, joins Bruno Bucciarati's team of Passione gang members in order to rise within the ranks and overthrow their mysterious boss, who is flooding the streets of Italy with drugs. By doing so, Giorno hopes to set the mafia's moral standards straight again. The group is also aided by Polnareff and Koichi who are members of previous Joestar Groups.
★: The character is leader (✩: Subsequent leader / ✦: Leader of their own faction within the group) (👻: The character remains as a soul or ghost)
☮: The character has resigned
⚓: The character retired (incapacitated) and/or their fate is unknown
★: The character is leader (✩: Subsequent leader / ✦: Leader of their own faction within the group) (👻: The character remains as a soul or ghost)
☮: The character has resigned
⚓: The character retired (incapacitated) and/or their fate is unknown
★: The character is leader (✩: Subsequent leader / ✦: Leader of their own faction within the group) (👻: The character remains as a soul or ghost)
☮: The character has resigned
⚓: The character retired (incapacitated) and/or their fate is unknown
★: The character is leader (✩: Subsequent leader / ✦: Leader of their own faction within the group) (👻: The character remains as a soul or ghost)
☮: The character has resigned
⚓: The character retired (incapacitated) and/or their fate is unknown
The main JoJos are assisted by a large group of allies, lead by Robert E. O. Speedwagon. Some of the allies had originally died and been possessed by DIO, but were freed from DIO's control and revived via the Saint's Corpse.
★: The character is leader (✩: Subsequent leader / ✦: Leader of their own faction within the group) (👻: The character remains as a soul or ghost)
☮: The character has resigned
⚓: The character retired (incapacitated) and/or their fate is unknown
Similarities
The majority of the Joestar Groups are not led by the main JoJo, but rather by an ally:
Phantom Blood's Joestar Group was initially led by Will Anthonio Zeppeli before his death, all the while he was teaching Jonathan Joestar the basic mechanics of the Ripple.
Stardust Crusaders' Joestar Group was led by Joseph, the eldest of the Crusaders, who initiates the mission to find DIO and fight him in Egypt.
Diamond is Unbreakeable's Joestar Group was led by Jotaro Kujo, the main rallying force for the active hunt for throughout the part.
Vento Aureo's Joestar Group was led by Bruno Bucciarati due to him being the direct superior of every member, in addition to him acting as a father figure to the group in general.
Stone Ocean's Joestar Group is the first group to be led by the main JoJo, Jolyne Cujoh. She leads the group's actions and commands the respect of her companions.
Steel Ball Run's Joestar Group is a partnership, with Johnny Joestar and Gyro Zeppeli agreeing to work together to reach each other's goals. However, Gyro possesses a tacit leadership role due to him teaching Johnny the Spin.
JoJolion's Joestar Group is the second group led by the main JoJo of the part, as Josuke's will to uncover his identity is the main drive behind the duo's actions and later he joins up with Rai Mamezuku in order to retrieve the New Locacaca branch.
Eyes of Heaven's Joestar Group is lead by Jotaro and Joseph, and their group of allies is lead by Speedwagon.
With the exception of Battle Tendency and Diamond is Unbreakable, most of the members in any Joestar Group die (or at the very least never seen again) before the end of their respective parts with very few carrying over to the next respective part. (i.e. Speedwagon, Joseph, Polnareff, Jotaro, and Koichi).
Diamond is Unbreakable and Jojolion share many similarities, mostly due to the latter being somewhat of an alternate-universe adaptation of the former:
Both main JoJos of the group are illegitimate children, and share the name Josuke Higashikata.
Both feature members of the Hirose Family, and each member shares a musical reference in their Stand's names with their respective Josuke - Diamond is Unbreakable's are both Pink Floyd songs, while JoJolion's are Prince songs.
Trivia
Though not initially planned, Araki threw around the idea of Hol Horse joining the protagonists of Stardust Crusaders during their journey, but opted out due to balance issues with Polnareff's similar character. Araki mentions this is part of the reason Hol Horse shows up multiple times throughout the story and why there is at least one group shot with Hol Horse present.[1]
Dio Brando once dismissively called Jotaro's own group the Joestar Egyptian Tour Group (ジョースター・エジプト・ツアー御一行様 , Jōsutā Ejiputo Tsuā Goikkōsama).[2]