Geum Jan-di

A swimmer who first appears while stopping a victim of bullying from committing suicide. As public opinion grows loud, Chairwoman Kang admits her to Shinhwa High School on a special scholarship to quiet the controversy. She earned the nickname 'Wonder Girl.' She has an upright personality. She gets a 'Red Card' after saving Oh Min-ji, but becomes involved with and loved by the self-centered Gu Jun-pyo. She gives up her dream of being a swimmer after her shoulder is ruptured while trying to protect Gu Jun-pyo, but eventually gets into Shinhwa University's medical school after three attempts. She addresses the F4 members as 'Sunbae' (senior), but always speaks informally to Jun-pyo. Female

Yoon Ji-hoo

The visual representative of F4. His specialty is the violin. He was the person Geum Jan-di trusted and relied on the most during her hard times. He overcame his trauma with the help of Min Seo-hyun. When Seo-hyun left for France, he followed her there, only to realize his feelings were admiration rather than love and returned. Thanks to Jan-di, he reconciles with his grandfather and eventually enters Shinhwa University's medical school with her. Male

So Yi-jung

The second son of a prestigious Korean artistic family that has maintained a reputation as national treasure-level potters for four generations. Although he has never failed to seduce a woman, he never dates with sincerity. He has an inferiority complex regarding his older brother; he broke up with his first love due to a misunderstanding that she liked his brother and has been unable to forget her. Eventually, he suffers a hand injury that makes it difficult for him to continue pottery. Male

Student

Female

Song Woo-bin

The heir to Ilshin Construction, a rising blue chip in the real estate industry. He lives the most 'normal' life among the F4 members. He is the most sociable and treats others with the most equality. Despite this, he is the least popular. Male

Ha Jae-kyung

She became Gu Jun-pyo's fiancée against her will through his mother, Chairwoman Kang. However, she gradually develops an interest in Jun-pyo. Upon realizing that he loves Geum Jan-di, she declares at their wedding that she does not want this marriage. Female.

Chu Ga-eul

She attends a pottery academy run by So Yi-jung's first love and has feelings for So Yi-jung.