If you haven't watched or read JoJo's Bizarre Adventure part 3, and you plan on it, I highly recommend doing so before reading this. As there will be spoilers in this.
You've been warned.
Disclaimer: I don't own the rights to anything I reference nor do I make money by doing this.
Jotaro Kujo has defeated DIO. The vampire's corpse lays lifeless on the ground after Jotaro's Star Platinum delivered the killing blow. It was a very difficult fight, that this Jojo won. Jotaro did lose his Grandfather, but he avenged that Jojo's death. As Jotaro stood there, the fact that he had won fully hitting him, he heard a loud and distant gunshot go off before a-
Nothing. Not a single thing. That's what Jotaro saw, felt, heard, smelled and tasted. This went on. Jojo had no idea how long this lasted. But, as he experienced the void and the void experienced him, he felt something. It wasn't anything specific, it was like he was in space moments beforehand. He could feel gravity weighing on, ground beneath his feat, clothes on his body. He could experience his senses again and he opened his eyes. Jotaro looked around, he appeared to be in what looked like some kind of slums. So, as he does, he walked around. He didn't like the clothing he was wearing, a white robe. He also wasn't entirely sure how he got here. He remembers going up some stai- "DIO!" Jotaro shouts out.
"Where's DIO? I have to stop him!" Jotaro said loudly to himself. He was getting weird looks, and this brought him to reality. He wasn't acting normally. Clearly something happened between him being in Dio's mansion and now. He just didn't remember. He was walking up the stairs with his friends and grandfather about to finally fight DIO face to face. Maybe an enemy Stand did this? Maybe this is all an illusion. "Star Platinum." Jotaro spoke aloud, summoning his Stand. Except, he got nothing. No big purple man.
"You must be new here, you look awful confused." A man speaks to Jotaro. Jotaro looks at him. "Can you tell me what's going on?" Jotaro asks. The man responds with, "You're dead." Silence follows that as Jotaro stares at him. "I'm dead?" Jotaro asks, not taking well to that. "Yes, you're dead. Everyone you see here is also dead, we were all alive once. Just like you were." The man explains.
Jotaro stands there as he takes this information in. This is either an enemy Stand or he really is dead and this really is the afterlife. If that's the case, the afterlife is kinda shitty. Jotaro, the genius, checked for his own pulse. Looking for something to prove anything. He felt no pulse… No pulse, no Star Platinum, a man telling him he's dead. All signs pointed to death, Jotaro did not like that at all.
Jotaro walked away from the man, where to? He did not know. He just walked. He was deep in his thoughts. When did he die? How did he die? Who else is dead? Did they win against Dio without him? Did they lose to Dio without him? Did Dio kill them all before they even had a chance to fight back? Anything was possible as it stood. While Jotaro walked around deep in thought, a man in black robes faced off against some sort of monster with a mask on its face. Jojo failed to notice this rather noisy encounter. He took notice of it right as the two combatants killed one another. The man falling to the ground while the monster faded into nothing.
"H-hey! You, come here." The dying man requested of Jotaro. Jojo complied with the wishes of the dying man. "You fought valiantly, what's your last request before you…" Jotaro's words trailed off as didn't know what happened to the already dead when they died. "T-take my s-sword. A-apply to the A-academy. Be-become a So-soul Rea-reaper bet-better than I-I ever could have been. P-please. Y-you. You're… str-strong. I can s-sen-sense it. Pl-please, d-do this." The dying man requested of Jotaro as he held out a simple katana in a plain white sheath.
"Good grief, I can't deny your dying wish and I'm low on options. So, fine. I'll do it. This should answer some question." Jotaro said, accepting the sword. "Th-thank you…" The man said as he passed away. Jojo didn't seem too happy about it, but oh well. This is what he was doing now, apparently. Now he just had to figure out what Academy he was talking about and what the hell a Soul Reaper was. Shouldn't be any problem, right?