As a marine biologist, he spent his spare time in Morioh writing an article on starfish for his doctorate. He is the grandson of Joseph Joestar, Nephew of Josuke Higashikata, father of Jolyne Cujoh. Sharp and always levelheaded, yet passionate in nature. He says “good grief” when he’s annoyed, and doesn’t need to speak to command his non-sentient and time-stopping Stand, Star Platinum. He’s never sad or concerned or scared. He never shows positive emotions with strangers.