Sixth grader Peter Lee, in a desperate attempt to regain the popularity he had in elementary school, discovers that serving detention can win him important friends, much to the dismay of his over-achieving eighth-grade sister, Sunny.
Zach is small for a sixth-grader and the girls at school make fun of him, but when one girl in his class starts showing him some Tae kwon do moves and teaching him about martial arts, things begin to change.
Albert Kim sees it as a miracle that popular, beautiful Mia Stone finds him worthy of her attention, but when her ex, Ryan Stackhouse, announces he has cancer, Mia is torn between being there for Ryan and her feelings for Albert.
As she reluctantly becomes friends with Yoon Jun, a new student from Korea, seventh grader Alice Larsen becomes more interested in learning about her own Korean background.