Since the day the Jung kids' mother died , their lives fell apart. Their mother was the one thing that held this family together. With their heartless father who left all of them one night, without a word, now, without a mother's support, four kids were left in a small, crumby, house. Moving to Korea was the only option for Changmin, Jessica, Taemin, and Yoogeun now. Where there was the only person who could take care of them. Their dad.

Now, the three oldest begin a new school, meet new people, and must use a language they're still rough at speaking, while trying to get closer to their new parent, who hoped to never see them ever again.

The three eldest transferred Choi-Cho High, later discovering the harsh rivalry towards Namlin Arts, a boarding academy was founded by Namlin Entertainment, where dreams of becoming a Hallyu idol may begin. Everyone who went to CCH, despised the snobs from Namlin. Whoever went to Namlin, hated Choi-Cho High students. 

After a weekend away from school,  a group Namlin rebels have crossed the line, vandalizing the CCH classrooms. During the months of remodeling, Namlin's punishment now was to share their school with Choi-Cho students.

Both schools are known to have the best arts programs in South Korea. So, how do they find out who the best school is? They compete against their artistic skills, of course! But what happens if someone becomes friends with someone from the other school? Or what if someone even falls in love with another from the rival school? Will they compete? Will they be kicked out? "Good Friends", you will see the conflicts, drama, and many different stories of Jessica and also at the point of view of various students on campus and see how they deal living with the people they hate the most.