Ryu Hee-jung

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...

Yuna is a teenage girl who just lost her mother and stepfather in a car accident. Without giving her time to mourn for them, suddenly, the elders of the stepfather's family claim that Yuna's mother can't be buried next to him since she's not their family member. Even her sister and brother don't take issue with their decision. Yuna believes all along that they were all a family but now, it looks like they aren't. If the mother's place isn't next to her husband, where should it be?