He is very handsome and is friends with Poo. He is playful and active, though not as much as Poo. He wears a red hat and light blue clothes. He is good at studying.

A yellow bear. He is cute. He is very playful, highly active, and hates studying. He wears a red cape and loves to play. He starts his sentences with "A-ha!"

Na-dongsaeng's older brother. He has a cranky personality but is very capable. He has gray hair and wears a white lab coat. He is excellent at studying, especially science.

Dr. Na's younger brother. He has a similar personality and appearance to Dr. Na. He is excellent at studying, especially science. (In short, he's the spitting image of Dr. Na.)