Na Rani

Female. Has a short orange bob. A certified beauty within the story's world. She is kind and gentle. While she tends to step back when sharing opinions, she steps up when necessary; she fits the heroine archetype. People around her always comment on her good personality. She loves experiments. She has a crush on Wonso. Close friends with Sena. Member of South Korea Team B.

Kang Wonso

Male. The son of the Star Group chairman, he is an all-rounder with excellent looks, intelligence, and athletic ability. However, he suffers from over 200 allergies, atopy, and various skin conditions; he has weak stamina and is sensitive to stress, making him physically frail overall. He doesn't trust others easily and has a cold, prickly style. He was originally kind and bright, but his personality turned sharp after a certain childhood incident, likely due to a distrust of people. He has since processed his trauma and accepted his teammates as friends. He seems to cherish them deeply. Though he bickers with Woojoo, they are 'frenemies' who share a deep bond, and Woojoo is a true friend to whom he shows his comfortable side. Member of South Korea Team B. Chic and blunt.

Ha Jiman

Male. Member of South Korea Team B. Has red curly hair. Dreams of becoming a reporter. Loves gathering information and is great at writing reports. The team's information specialist. Likes Elizabeth. He joined the club because of Woojoo, but now he genuinely loves experimenting.

Elizabeth

Female. Nicknamed Liz. Likes Jiman. Member of UK Team B. Very intelligent. Has long brown curly hair, freckles, and wears glasses.

Kang Sena

Female. A self-centered and proud daughter of a wealthy family. Childhood friend of Heo Hong and Kang Wonso. She has feelings for Max and eventually dates him. Member of Germany Team A.

Max Bauer

Male. Handsome. Basically chic, cool, and active. Despite his cool exterior, he is surprisingly delicate and kind. He has a bit of a tsundere streak. Unlike his chic vibe, he is polite and friendly to everyone. He loves handball. He likes Sena and eventually dates her. Member of Germany Team A.