Works as a marine biologist. He is usually cold toward Polnareff but occasionally shows a sudden flash of kindness. Even when Polnareff is teasing him, he just says "Good grief" (Yare yare daze) with a faint, exasperated smile. He doesn't get angry easily, but he does get annoyed. Jotaro is not very expressive. He is the type to stay quiet and listen to Polnareff talk. He is 198cm tall—a 5cm difference from Polnareff!