Masao Sato (マサオ) (5 years old), Max in the Vitello and Phuuz dubs, is one of Shin-chan's friend and classmate from the sunflower class. He is a weak, sensitive boy, and is scared of many things. Even though Masao is known to be spineless, there was once when he betrayed Shin-chan over a pack of candies with the others (Bo, Nene, and Kazama, though only they feel sorry), but eventually comes back to save him after feeling guilty of what he did. He can be easily embarrassed, but believes his and Ai's love can conquer anything. He has been in love with Megumi Yamura. He gets upset when Ai pursues Shin-chan and Shin turns down Ai's advance.