He is very, very handsome and is friends with Poh. He is mischievous and active, though not as much as Poh. He wears a red hat and light blue clothes. He is good at his studies.

A yellow bear. He is cute. He is very mischievous, extremely active, and hates studying. He wears a red cape and loves playing around. He starts his sentences with "Oho!"

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 his studies, especially science.

Dr. Na's younger brother. He has a similar personality and appearance to Dr. Na. He is excellent at his studies, especially science. In short, he's a carbon copy of Dr. Na.