"Human Classroom" tells the story of a model student who commits a serious crime in order to make money, and his friends and people around him are inadvertently involved in the crime, which leads to conflicts and incidents, as well as the loss of humanity. Kim Dong-hee plays the role of Ji-soo, a high school student who makes the wrong choice in order to raise college tuition. Jung Da-bin plays the role of Min-hee. Min-hee is a classmate who is involved in Ji-soo's crime and falls into chaos. Park Joo-hyun plays Gyuri, who is in the same high school as Ji-soo and is a character who accidentally learns about Ji-soo's crime and participates in the crime.