Mysterious fairies who appeared to Seoyeon and Minho one day. Just like the saying "Puberty has arrived," they appear to all children when the time for growth comes. They play a role in growing the body and mind with mysterious powers. They are invisible to others, but some children can see them. Minho's Puberty Fairy: Energetic and mischievous personality. Seoyeon's Puberty Fairy: Energetic and cheerful.

An energetic and mischievous boy who often teases Seoyeon.

A first-year girl at Our Middle School who is expressive and quick-witted. She appears energetic and bright, but possesses a cautious and delicate heart. She can see the Puberty fairies but pretends not to in front of her friends. She has a bit of a crush on Minho, but she doesn't realize it yet.

He tends to be indifferent to things happening around him, but treats his close friends' business as his own. Personality: ENTP Best friends: Jongcheol, Minho

Best friend to Minho and Hyeonseok, he loves acting like a know-it-all. In reality, he actually does know more than most kids his age.

Seoyeon's best friend. She likes Seoyeon very much (as a friend), follows her lead, and is a deep thinker.

She became close to Seoyeon through Miji, and the three of them go everywhere together. She cannot stand injustice.

Sweet and very kind.

Expresses interest very actively.

The characters' parents: Minho's Dad: 34 years old, handsome, slightly thin build, somewhat cold but energetic personality. Seoyeon's Dad: 42 years old, somewhat cute and cries easily. Minho's Mom: 40 years old, warm and slightly energetic personality. Seoyeon's Mom: Warm and kind personality.