Warning! Spoilers ahead for JoJo's Bizarre Adventure Part 8
One of the unique things about JoJo's Bizarre Adventure is that it's a family saga, passing the torch from one Jojo to the next, all the way from Jonathan Joestar in the 1800s to Jolyne Cujoh in the modern day. When the story hit its seventh chapter, Steel Ball Run, it brought some of the concepts like Stands back to that initial time period, effectively rebooting the story and telling it again in a different way. While it seemed like things would be very different this time around, fans were shocked to hear, back in 2011, that the star of Part 8 would be Josuke Higashikata again, even if he looked different. So why Josuke again, and is he really even the same character?
The fourth chapter, Diamond is Unbreakable, originally starred Josuke and was set in 1999. Josuke is drawn into the world of Stands, soul-based powers that are unique to each person, by the discovery that he is an illegitimate son of Joseph Joestar. Josuke is a high schooler at the time, and finds himself pitted against a Stand-empowered serial killer named Yoshikage Kira, an older businessman who preys on women. Many of the series' most famous and iconic moments are set in this part, and mangaka Hirohiko Araki has said that Josuke is his personal favorite. Diamond is Unbreakable is also unique in that it features both previous still-living JoJos in supporting roles, giving fans a bit more time with Jotaro and Joseph.
Jojolion, the eighth part, was announced to follow Josuke Higashikata, and stated that it would be set after the Tohoku Earthquake and tsunami in 2011. The character, however, now possesses a different Stand, which would seem to indicate that he isn't the same person. It turns out that the name Josuke is given to him after he's discovered with amnesia, so this might seem like little more than an in-joke. But, as is standard for Jojo, things continue to get weirder, and the investigation of his identity leads to an apartment belonging to Yoshikage Kira, now a ship's surgeon who has gone missing. It's revealed that Kira's family branched off a few generations ago, but can be traced back to Johnny Joestar of Part 7, meaning that he does indeed have the Joestar blood.
This doesn't sit right with Josuke, and it's true that he is more than simply Kira with another name. In this timeline, Kira had a friend whom his mother saved as a child named Josefumi Kujo, who bears a striking resemblance to Diamond is Unbreakable's Josuke. The pair were working together to find a way to save Kira's mother Holly Kujo, again suffering from a mysterious illness. They hoped to locate one of the miraculous fruits that she'd used to save Josefumi, thinking it could save her as well. Though they succeed in acquiring some of the fruit, Kira is fatally wounded during a showdown and Josefumi is barely able to drag him ashore. In a desperate attempt to save his life, Josefumi feeds the fruit to Kira...and Kira starts to heal, as aspects of Josefumi are taken away. The amnesiac Josuke is neither Kira nor Josefumi, but rather a fusion of both into a single person. The color of Josuke Higashikata's eyes is split in half as an indicator of this, and his anatomy is quite odd as a result.
This unique remix of familiar elements helps to set Jojolion apart from other reboots, maintaining the strangeness and drama that fans love about Jojo's Bizarre Adventure while playing with established characters in a new light. Aside from Kira and Josuke, Holly Kujo was seen before as Joseph's daughter and Jotaro's mother in Part 3, where she wasn't given much opportunity to develop. This time around, she's a doctor and seems more in tune with the family strangeness. There are also additional flashbacks which reveal the ultimate fate of Steel Ball Run's Johnny, who moved to Japan after that story ended, radically changing the Joestar family history from how it once played out. His family surname becomes Higashikata, making nearly all of the characters in Jojolion Joestars by blood.