Male 17 years old Korea Team B A troublemaker who prefers playing over studying. A friend who is always getting nagged(?) by Won-so (but they still get along well). A hidden talent who occasionally shows his true skills at crucial moments. He has a crush on Na Ran-yi.

Female 17 years old Korea Team B A hard-working genius who loves science. Kind to everyone. She gets hurt easily because of her sensitivity, but she overcomes it well. She has a crush on Kang Won-so.

Male 17 years old Korea Team B The only son of a chaebol family. Leader of Korea Team B. Born with a weak constitution due to allergies and chronic illnesses. Has strong pride. Very smart, especially excelling in anything science-related. Goes to exercise (like basketball) when he's stressed. Nags(?) Beom Woo-joo.

Male 17 years old Korea Team B Specializes in information gathering. Can be seen obsessing(?) over information. Always carries a notebook and pencil to collect data. Because of this, he always knows (heaven knows where from) tournament information. However, he maintains a serious attitude when it comes to science.

Male 17 years old USA Team A Leader of USA Team A. Won the championship with USA Team A last year due to his excellence in science theory and experiments. Has a slightly cold style but is nice to people he likes. Always calculating things in his head. Thinks Beom Woo-joo is interesting(?).

Male 17 years old UK Team A A genius science boy from the UK. Kind but has a slightly jealous streak. A leader who proposes ideas and takes the initiative in the team.

Male 17 years old Korea Team A Participated in the Science Olympiad last year but remembers losing to the USA team (they get along well now). A hard-working genius who understands well and puts in effort, though not quite at Eric's level. Loves nuts like almonds and walnuts, so he always carries them around.

Male 17 years old China Team A Playful and sometimes sly. His skills are hidden behind his funny appearance, making him one of the top candidates for the winning team. Shows a somewhat unique personality.

Male 17 years old Japan Team A Good at and loves science-related experiments. Slyly observes others to figure them out. If he likes someone, he continues to be sly only toward that person. Has a unique side, such as brewing potions like love elixirs.

Male 17 years old Germany Team A Good at both sports and science. When doing science, he enjoys the process rather than just studying it. Cheerful and warm-hearted. Enjoys experimenting more than the thought of having to win the competition. Always the type to take care of others first.