Yoshida (14 years old) is the inkya (not social, dark etc.) of the class. One day, he is seated next to Shigure-san, an inkya girl. After Shigure-san realizes that Yoshida is one of her kind, she starts to call out to him, all of a sudden...! The dark duo engages in a heated battle to become the youkya (happy/sunny person)! (Source: Shueisha, translated)