Plot: A furious Choi Gyung becomes suspicious when Je-i nominates Seul-gi as class monitor. Ju Ye-ri overhears a conversation about Je-i's former seatmate
Cast
Lee Hye-riYoo Je-yiLee Hye-ri was 30 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Thu, Jun 09 1994
Chung Su-binWoo Seul-giChung Su-bin was 26 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Mon, Aug 17 1998
Kang Hye-wonJoo Ye-riKang Hye-won was 25 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Mon, Jul 05 1999
Oh Woo-riChoi GyeongOh Woo-ri was 28 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Tue, Aug 06 1996
Kim Tae-hunYoo Tae-joonKim Tae-hun was 49 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Mon, May 26 1975
Chae Seo-eunJo Ah-raChae Seo-eun was 26 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Fri, Oct 23 1998
Choi Young-jaeNam Byeong-jinChoi Young-jae was 28 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Tue, Sep 17 1996
Kim Sang-jiBeom-sooKim Sang-ji was 24 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Sat, Jul 15 2000
Lee Won-jaeWoo Do-hyeokLee Won-jae was 47 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Sun, Jan 22 1978
Yoo Jung-RaeHomeroom TeacherYoo Jung-Rae was 36 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Mon, Dec 19 1988
Kang Jin-ahKwon Hee-yoonKang Jin-ah was 39 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Thu, Feb 06 1986
Ma Hyun JiPark Byeong-huiMa Hyun Ji was 27 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Tue, Jan 27 1998
Choo Ye-jinYoo Je-naChoo Ye-jin was 23 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Thu, Oct 11 2001
Ha-minPrincipalHa-min was 55 in Friendly Rivalry - Season 1 - Episode 4 (Episode 4).
Birthday: Sat, Sep 20 1969