Age: 12 Gender: Male Affiliation: Gosu Elementary School Invention Club A Brown hair, thick eyebrows. Handsome. Relaxed, confident, and free-spirited. Possesses excellent intuition and quick wits. Acts as Cho Yena's right-hand man. Tends to look after Bang Gap-su especially well. Maintains relatively good relations with Club B.

Gender: Male Age: 12 Affiliation: Gosu Elementary School Invention Club A Orange permed hair and blue eyes. Ordinary appearance. Arrogant due to being from a wealthy family. Somewhat eccentric. The mood maker of the team. Colleague of Yena and Myeong-in. Particularly close to Myeong-in. Friendly with Club B. Likes Cho Yena, so he is jealous of Han Dae-beom.

Gender: Male Age: 12 Affiliation: Gosu Elementary School Invention Club B A handsome boy with spiky yellow hair. Possesses genius-level invention skills and a strong sense of purpose. Kind and energetic. Has a special relationship with Yena. Originally a member of Team A before leaving the club.

Gender: Female Age: 12 Affiliation: Gosu Elementary School Invention Club B An energetic girl with a pink bob cut. Bright, proactive, and possesses excellent analytical and presentation skills. Can be blunt. Teammates with On Yu-han, Jang Jae-ju, and Han Dae-beom; they are all very close. She is the duo that bickers most frequently with Jang Jae-ju.

Gender: Male Age: 12 Appearance: Handsome Affiliation: Gosu Elementary School Invention Club B Purple-toned hair, styled in a ponytail early on, later cut short. Kind, diligent, and takes good care of his friends. Strong in design and ideas. Teammates with Han A-reum, Jang Jae-ju, and Han Dae-beom. Used to have a crush on Han A-reum.

Gender: Male Age: 12 Affiliation: Gosu Elementary School Invention Club B Black-toned hair, wears glasses. Ordinary appearance. A lazy person who hates bothersome things. Playful and loves plastic models (Giga Kaiser) very much. Childhood friends with On Yu-han. Constantly bickers with Han A-reum (e.g., calling her 'Rice Cake Face').

Gender: Female Age: 20s-30s Affiliation: Gosu Elementary School Invention Club Advisor Has a purple and gray short cut and wears round glasses. Appearance is cute and pretty. Kind and gentle. Has a clumsy streak.