本片是一部Mystery片，由Ryu Hee·jung导演，由Jo Hye·won/Lim Ji·sub/Kim Woojin主演。
剧情简介：In the prestigious Shinha High School, there is a secret hidden between the third and fourth periods. There are 3.5 classes where time goes 10 times slower and 10 minutes becomes 100 minutes! Baek Ah-jin accidentally enters the 3.5th period and meets Kang Da-won, a male student who was trapped there. To escape Dawon from the 3.5th period, Ahjin solves the mystery hidden there. But there are people in the school who try to hide 3.5 classes...
外文名：3.5 교시
类型：Mystery / Romance / Fantasy
导演：Ryu Hee·jung
演员：Jo Hye·won / Lim Ji·sub / Kim Woojin / Song Young·gyu / Kang Byul / Kwon Go·eun / Lee Pu·reum / Park si yun
