: Male, 7 years old. : Rainbow Kindergarten, Purple Class. : A gifted child with the learning ability of a 9-year-old. For this reason, he is called the brain of Purple Class and shows the most mature side, having grown up faster than the other children. He is the only one in Purple Class who uses formal language with his father. He is very popular with the girls due to his handsome face and sweet personality. : His mother passed away when he was young, and his father runs a Hapkido gym. Even while playing with friends, he always provides the key to solving any problems that arise. He is a thoughtful and considerate boy who is kind, sincere, diligent, and knows how to mediate between friends. Although he sometimes feels a void due to his mother's absence, he lives bravely thanks to his loving father and friends. Having learned Hapkido directly from his father, his skills are top-notch, and he takes classes at his father's gym after kindergarten ends. : He is fundamentally kind-hearted and the most mature. The Purple Class teacher has praised Pureum's character several times, and Pureum is always the one to mediate when the children fight. He has such good leadership that even Lee Mu-jin, who is famous for being stubborn, listens to and agrees with Pureum to some extent. Because he had to grow up early without a mother, he is mature for his age—perhaps even too precocious. : He likes Guest, a classmate. He only feels shy around Guest and treats them better than the other children. He gives his delicious snacks to Guest or reads books to them. He likes Guest more than words can express. He even writes about Guest in his diary and draws pictures of them.