Series Cast 26

1. 

   Byeon Woo-seok

   Ryu Sun-jae (16 Episodes)

2. 

   Kim Hye-yoon

   Im Sol (16 Episodes)

3. 

   Song Geon-hee

   Kim Tae-sung (16 Episodes)

4. 

   Lee Seung-hyub

   Baek In-hyuk (16 Episodes)

5. 

   Jung Young-ju

   Park Bok-soon (16 Episodes)

6. 

   Seong Byeong-suk

   Jung Mal-ja (16 Episodes)

7. 

   Song Ji-ho

   Im Geum (16 Episodes)

8. 

   Seo Hye-won

   Lee Hyun-joo (16 Episodes)

9. 

   Kim Won-hae

   Ryu Geun-deok (16 Episodes)

10. 

    Ahn Sang-woo

    Kim Seok-hyun (16 Episodes)

11. 

    Lee Il-jun

    Park Dong-seok (16 Episodes)

12. 

    Yang Hyuk

    Jay (16 Episodes)

13. 

    Moon Yong-seok

    Hyun-soo (16 Episodes)

14. 

    Park Yoon-hee

    Kim Won-chul (16 Episodes)

15. 

    Jeon Yeong

    Lee Kyung-ja (16 Episodes)

16. 

    Go Tae-jin

    Choi Jung-hoon (16 Episodes)

17. 

    Heo Hyung-kyu

    Kim Young-soo (16 Episodes)

18. 

    Han Seung-yeon

    Self (2 Episodes)

19. 

    Lee Chul-woo

    Kim Hyung Gu (Seon Jae's rival) (1 Episode), — (1 Episode)

20. 

    Kwon Yu-ri

    Self (1 Episode)

21. 

    Park Tae-hwan

    Self (1 Episode)

22. 

    Lee Su-ji

    Cheonsin (1 Episode)

23. 

    Kim Min-ki

    Kim Do Jun (1 Episode)

24. 

    Cho Ryun

    In Hyuk's mom (1 Episode)

25. 

    Song Yeong-jae

    In Hyuk's dad (1 Episode)

26. 

    Ko Seo-jeong

    Math Teacher (1 Episode)

Series Crew 3