The new season will take place in a college setting, showing the growth and romance of young people as they prepare to enter the real world.

It tells the love and friendship stories of teens. It is a new semester with new faces. Yun Doo is now in the last year of high school. Her life is complicated with misunderstandings and conflicts. What should she choose love or friendship?

Best Mistakes starts with Yun Doo accidentally posting a photo of Hyun Ho on her social media account to warn off a stalker. When Hyun Ho finds out, he confronts Eun Jae and this marks the beginning of their love/hate relationship.