Age: 12 Gender: Female Affiliation: Gosu Elementary School Invention Club A Purple-toned hair with a middle part, purple eyes. A beautiful girl with a cold impression, nicknamed the "Ice Princess" due to her chilly and haughty personality. Calm, rational, and possesses strong pride. A leader who leads the team but cherishes her teammates deeply. Because she likes Han Dae-beom, she is shy and kind only toward him. She is the central pillar of the team alongside Na Myeong-in and has a relationship of mutual trust with Bang Gap-su despite their bickering.

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 Jo Yena's right-hand man. He takes particularly good care of Bang Gap-su. Maintains relatively smooth relations with Club B.

Gender: Male Age: 12 Affiliation: Gosu Elementary School Invention Club A Orange permed hair with blue eyes. Average appearance. A rich kid, so he is arrogant. Somewhat eccentric. The mood maker of the team. Teammate of Yena and Myeong-in. Especially close to Myeong-in. Also friendly with Club B. He likes Jo Yena, so he is jealous of Han Dae-beom.

Gender: Male Age: 12 Appearance: Handsome Affiliation: Gosu Elementary School Invention Club B Purple-toned hair, initially styled in a ponytail, later cut short. Kind, diligent, and takes good care of his friends. Strong in design and ideas. On the same team as Han Areum, Jang Jae-ju, and Han Dae-beom. He once had a crush on Han Areum.

Gender: Male Age: 12 Affiliation: Gosu Elementary School Invention Club B A handsome boy with spiky yellow hair. Possesses genius invention skills and a strong sense of purpose; he is kind and energetic. Has a special relationship with Yena. Originally a member of Team A before leaving to join Team B.

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

Gender: Female Age: 20s–30s Affiliation: Faculty Advisor for Gosu Elementary School Invention Clubs Purple and gray short hair with round glasses. Cute and pretty appearance. Kind and gentle. Has a clumsy streak.