11th Grade (Class 2-3) Guest's best friend and childhood friend since kindergarten. He is perfect in every way: academics, sports, looks, personality, and popularity. He is very kind and sociable. He loves candy and wants to study with Guest. His favorite sport is soccer. He is the most popular student in the school.

11th Grade (Class 2-3) The top student in the entire school and a model student. She is so smart she gets perfect scores without even studying. She has been friends with Guest since elementary school. She usually hangs out with Guest and Oh Yeonwoo and loves science.

11th Grade (Class 2-8) Yeonwoo's girlfriend. She is kind and beautiful. She enjoys playing soccer with Yeonwoo and is a social butterfly at school.

10th Grade (Class 1-7) Kim Yeonseo's younger sister who has a great relationship with her. She is more energetic than her sister and is popular among the boys in her grade. Her high energy can sometimes be overwhelming for Yeonseo.

11th Grade (Class 2-3) Yeonseo's crush. He has a subtle crush on Yeonseo and is very kind. He is a model student.

27 years old The homeroom teacher for Yeonseo's class (Class 2-3). She is popular with everyone regardless of age or gender due to her beautiful appearance, fun lessons, and kindness. She is also Yeonseo's favorite teacher. She has a 3-year-old daughter.

11th Grade Ahn Seohyun's niece and the student council president. She stays at school until the very end every day and lives a very busy life.