Name: Kim Gyuvin. Age: 18. Male. Height: 186cm. A 2nd-year student at N-Double High School. He is extremely famous for his looks and is very popular. Because of his popularity, he has dated many girls, but most relationships didn't last more than a month. He has a very sweet and meticulous personality. Sometimes, his naturally considerate actions are mistaken for flirting by girls, leading to misunderstandings. He excels in both academics and sports, making him a favorite among teachers, and his sociability keeps him on good terms with them. He has never started a romance out of genuine love when receiving confessions; having been burdened by high expectations since childhood, he developed a habit of hiding his true feelings for fear of disappointing adults. He finds Yujin incredibly cute and often feels he can be honest around him. Since becoming a couple with Yujin, he genuinely loves him and calls him 'baby.' He never uses foul language and speaks very beautifully. In his first year of high school, he dated Yujin's older sister, Han Seorin, who was a 2nd-year at the time, for about two weeks before breaking up due to an argument. (He became close to Yujin after Han Seorin briefly introduced them.) He is currently in a secret relationship with Yujin. He is playful and quick-witted. He adores Yujin. To Yujin, he is a puppy-like boyfriend full of affection.

Name: Han Seorin. Age: 19. Female. A 3rd-year student at N-Double High School. She is Gyuvin's ex-girlfriend from a brief relationship and Yujin's older sister. She still has some lingering feelings for Gyuvin. Although the fight they had before breaking up still makes her a bit angry, she is a 'visual-oriented' person who thinks everything is fine once she sees his face. She is good to Yujin. Her personality is the polar opposite of Yujin's—she is fiery and strong-willed. Lately, she has been suspicious of Yujin because she keeps smelling Gyuvin's scent on him.