Main •
Park Ji-hu as Song Woo-yeon (Baby Blue Finger) • Park So-ye as young Woo-yeon : A high school girl who lacks self-confidence. She is shy and doesn't dare to express herself. But after she meets the Spirit Fingers Club, her boring life becomes lively again. •
Cho Jun-young as Nam Gi-jeong (Red Finger) : A charismatic high school student with a part-time gig as a fitting model and Gue-rin's younger brother. He has never experienced true love. After Woo-yeon appears, he begins to have dreams and love like everyone else. •
Choi Bo-min as Koo Seon-ho (Blue Finger) : The vice president of the Spirit Fingers Club, he has a gentle personality and is a handsome boy who is popular among everyone in university. With his good looks and outstanding talent in arts and sports. •
Park You-na as Nam Geu-rin (Mint Finger) : The president of the Spirit Fingers club and Gi-jeong's older sister. She cheerful and bright who takes care of Song Woo-yeon like her little sister.
Supporting Spirit Fingers Club •
Kwon So-hyun as Hwang Bun-hong (Pink Finger) •
Kim Seul-gi as Ko Taeng-ja (Black Finger) •
Lee Jin-hyuk as Kwon Hyeok (Khaki Finger) •
Im Chul-soo as Jang Dong-geon (Brown Finger)
People around Woo-yeon • Eun Yeo-jin as Yeom Se-ra : Woo-yeon's best friend who is smart and charming. She lives with her father after he divorces her mother. • Chae Soo-ha as Jo Mi-rae : Woo-yeon's best friend. •
Kim Hye-eun as Seong Kyeong : Woo-yeon's mother, who gave up her ballet career to care for her children. • Ki Eun-yoo as Song Woo-dol : Woo-yeon's younger brother, who is intelligent and mature beyond his years. • Son Hyun-woo as Song Woo-seok : Woo-yeon's older brother, who is studying medicine and only returns home occasionally. • Joo Suk-tae as Woo-yeon's father : Woo-yeon's father is a teacher and has high hopes for his children's academic performance.
People around Gi-jeong •
Kang Hye-won as Ahn Ye-rim •
Cha Woo-min as Byun Tae-seon : Gi-jeong's best friend. •
Ham Sung-min as Oh Dae-oh : Gi-jeong's best friend. ==Production==