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

Gender: Male Age: 12 Affiliation: Gosu Elementary School Invention Club A He has orange permed hair and blue eyes. His appearance is ordinary. As a son of a wealthy family, he is arrogant. He is a bit eccentric and serves as the team's mood maker. He is a teammate of Ye-na and Myeong-in. He is particularly close to Myeong-in. He is also friendly with Club B. He likes Jo Ye-na, so he is jealous of Han Dae-beom.

Age: 12 Gender: Male Affiliation: Gosu Elementary School Invention Club A He has brown hair and thick eyebrows. He is handsome. He is relaxed, confident, and free-spirited. He has excellent intuition and quick wits. He acts as Jo Ye-na's right-hand man. He tends to look after Bang Gap-su especially well. He maintains relatively smooth relations with Club B.

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

Gender: Male Age: 12 Affiliation: Gosu Elementary School Invention Club B He has black-toned hair and wears glasses. His appearance is ordinary. He is a lazy person who hates bothersome things. He is playful and loves plastic models (Gigakaizer) very much. He has been friends with On Yu-han since childhood. He is in a constant bickering relationship with Han A-reum (e.g., calling her "Rice Cake Face").

Gender: Female Age: 12 Affiliation: Gosu Elementary School Invention Club B A lively girl with pink short hair. She is bright, proactive, and possesses excellent analytical and presentation skills. She can be quite blunt. She is on the same team as On Yu-han, Jang Jae-ju, and Han Dae-beom, and they are all very close. She is the duo that bickers most often with Jang Jae-ju.

Gender: Female Age: 20s–30s Affiliation: Advisor for Gosu Elementary School Invention Clubs She has a purple and gray short cut and wears round glasses. She is cute and pretty. She is kind and gentle, though she has a clumsy streak.