Kai has just transferred to SMA Bina Indonesia. She meets Kenan, Ale, Aurora, and Re: four geniuses Kai soon ranks higher than in the school’s ranking system. Kai seems to make herself Enemy Number One to the four of them, until an incident breaks Kai's heart... and the hearts of the entire school.

Kai starts to get to know Aurora, and despite her “bad girl reputation," turns out to be suffering from her father's big obsession. Aurora crosses paths with Tyo, and starts to realize for herself that something isn’t quite right about her father.

Behind Re’s annoying attitude that Kai finds unbearable, Re really loves his sister Jo, who is suffering from a critical illness. Kai quickly becomes Jo’s friend, which brings her closer to Re. Together, they smell something fishy about the school's ranking system.

Kai, with the help of Re, Aurora, Kenan and Ale decide to take action to disrupt the mock exams and bring the school ranking system to its knees. Kenan finds out that all this time, a key individual close to Re has been playing a major role in the ruthlessness of the school’s ranking system.

With the friendship of the five under threat, Ale still believes in the strength of their bonds. Kai finds faith in Ale while learning to open her heart to Re. Ale discovers that she and Aurora are united by a secret from the past.