Main
- Kang Daniel as Wi Seung-hyeon,
- Chae Soo-bin as Go Eun-gang,
- Oh Ah-rin as young Go Eun-gang.
- Lee Shin-young as Kim Tak,
- Park Yoo-na as Ki Han-na,
Supporting
Students
- Park Sung-joon as Yoo Dae-il,
- Min Do-hee as Woo Joo-young,
- Kim Woo-seok as Seo Beom-joo,
- Cheon Young-min as Shin Ah-ri,
- Park Yeon-woo as Kang Joo-chan,
- Jung Soo-bin as Baek Seon-yoo,
- Kim Seung-ho as Pyo Hyun-seok,
- Lee Joon-woo as Uhm Hyuk,
Faculty
- Kim Sang-ho as Cha Yoo-gon,
- Seo Yi-sook as Kim Soon-young,
- Choi Woo-ri as Bang Hee-sun,
Family
- Son Chang-min as Wi Ki-yong,
- Lee Moon-sik as Go Yang-cheol,
- Jung Young-joo as Lee Hee-sook,
- Son So-mang as Go Mi-gang,
- Sa Kang as Ki Han-na’s mother.
Others
- Kim Yool-ho as Choo Yi-sa,
- Hyun Woo-sung as Kang Nam-gi,
- Park Ji-hoon as one of the bullies at the billiard hall.
- Lee Woo-je as one of the bullies at the billiard hall.
- Ahn Do Kyu as Hong Yoon-ki,
- Kim Kwon as Jo Han-sol,
- Jung Yeo-Jun as Shin Ui-seok,
Special appearances
- Kwak Si-yang as Kim Hyun-soo,
- Shin Ye-eun as Jang So-yeon,
- Choi Jae-hyun as Min-yong, Wi Seung-hyeon’s friend.
- Park Sang-nam as Go Eun-gang’s blind date.
- Go Yoon-jung as Blind date’s profile photo
[rve src=”https://www.youtube.com/watch?v=kxfMEQgSDJA” ratio=”16by9″]