It mainly focuses on portraying realistic issues that South Korea's youth faces, such as the corrupt education system, teen suicide, corporal punishment, academy and tutoring culture, career prospects and bullying.
Go Nam-soon (Lee Jong-suk) is elected class president for grade 2, thanks to the support of Oh Jung-ho (Kwak Jung-wook), who is a member of the school gang.
Now, Jung In-jae (Jang Na-ra) and Kang Sae-chan (Choi Daniel) becomes the homeroom teachers of the students whose philosophies are apparently at odds.
Together, they manage Victory High's toughest class; facing bullies, academic underachievers, and demanding parents, as they help the students overcome their problems.
The plot follows a class of high school students attempting to overcome the stress of being ranked by their exam grades, and facing the difficulties of being a teenager in a high-pressure, corrupt system.
Its central protagonist is Ra Eun-ho (Kim Se-jeong), a cheerful and kind-hearted 18-year-old who dreams of being a webtoon artist but is caught up in the search for a mysterious troublemaker in the school, known as 'Student X'.