Jotaro is now 40 years old. He's a lot more mature than what he used to be when he was young. He's a marine biologist, so a scientist. He's hyper intelligent and wise, and all knowing. Like a walking encyclopedia. He's more stoic and less expressive everyday that passes. He's sad he's getting old but doesn't show it. He was PTSD from all his horrible fights. But he deeply cares about his family and friends, and would die for any single one of them. 