After starring in mostly music videos, his appearance in "School" (1999) quickly made him a celebrity overnight. Jang Hyuk emerged as every male student's wannabe and female students' ideal man for his "bad boy" character in the series' first installment.

Here's a fun fact- Gong Yoo, Lee Dong Wook and Yook Sung Jae of "Goblin" all starred in the "School" series! Lee Dong Wook appeared first in the series, actually playing the role of high school romantic guy Lee Kang San in back-to-back seasons, first in "School 2" (1999) then "School 3" (2000). "School 4" (2000) actually marked Gong Yoo's debut as an actor. Similarly, "Who Are You: School 2015" was also the debut production for BTOB's Yook Sung Jae.

Kim Min Hee's role as a troubled teen in "School 2"(1999) -- alongside Ha Ji Won-- helped solidified her place as an actress, even earning her a Young Actress Award. For her co-star, actor Kim Rae Won, "School 2" was his second production as an actor, and it also won him the KBS Young Actor award.

Contrary to her elegant and graceful image, Soo Ae appeared as a "ssen-unnie" who bullied her classmates in "School 2" (1999).

School 3 (2000) marked Jo In Sung's debut as an actor, even winning him a KBS Young Actor Award.

The actress had debuted in 1996 with the teen drama, "New Generation Report: Adults Don't Understand Us." But it was her role as Jang Se Jin, a rebellious high school teenager, in "School 2" (1999) that really brought her into the spotlight.

The actress's debut in "School 4" (2001) was her only other role in a drama series, aside from the 2004 hit drama "I'm Sorry, I Love You."

The best friends and model-turned-actors appeared together in "School 2013." Some reportedly thought they were dating because of their close friendship on the set. Kim Woo BIn perfectly responded to the rumors, saying that "friendship is a kind of love."

Lee Yuri showcased her outstanding talent as an actress early, appearing as a rebellious teen in "School 4" (2001). Although she had a supporting role, she rose to the level of fame of a leading role, snagging the Young Actress Award.

Both actresses won a KBS Best New Actress award for their roles in School 1999, the first installment of the series. The drama was also the debut production for Bae Doo Na, who is now also active in Hollywood.