4th Period Mystery

Plot

Jung-hoon (Yoo Seung-ho) is the best student at his school. His rival, Tae-gyu (Jo Sang-geun), takes any and every opportunity to knock him down both verbally and physically, and the two are known enemies amongst the other students. One afternoon Tae-gyu pushes Jung-hoon too far and the latter threatens Tae-gyu with a knife, an act that's witnessed by another student. Jung-hoon walks away from the situation, but shortly after the beginning of 4th period class he returns to find Tae-gyu dead. The boy has been stabbed repeatedly, and still in shock, Jung-hoon picks up the bloody knife off a nearby desk just as Da-jung (Kang So-ra) shows up, catching him in a most incriminating position. Fortunately for him, she not only believes his innocence, but offers to help him to solve the mystery and catch the real killer – a task made particularly urgent by the fact that in 40 minutes the rest of the class will return and the body will be discovered. The pair set out in search of the murderer and soon discover that just about everyone's a suspect and even more unsettling, the murderer is now after them as well.

Cast

Yoo Seung-ho as Han Jung-hoon

Kang So-ra as Lee Da-jung

Cho Sang-geun as Kim Tae-gyu

Jeon Joon-hong as Byung-soo

Jeong Seok-yong as Kang Guk-man

Park Chul-min as Han Kang-man

Lee Young-jin as Sang-mi

Kim Ji-eun as Student

Kim Dong-beom as Do-il

Lee Chan-ho as Tak Teu-in

Min Kyung-jin as Principal

Im Soo-hyang

Sung Hyuk as a gym teacher

Kim Yeong-ung as a history teacher

Production

Casting

Originally, actress Kim So-eun was going to play the role of Dajung but she was replaced with Kang sora because of Kim's filming schedules for the TV series He Who Can't Marry.

Filming locations

The film was filmed in Sungsa Middle School in Goyang.

Indian remakes

The 2016 Tamil movie Pencil is a remake of the movie. Also, the 2018 Bengali movie Classroom is another remake of the movie.