From Chibi Manga:

Sawa is a representative of the student council and the valedictorian of her grade. A teacher had asked Sawa to persuade Tatsuki who has been ditching school and have not been attending his classes. But when she goes to the Educational Guidance Room to speak with him she sees him fooling around with a girl. She decides to go to his house to talk to him, but he takes her out with him and tells her, “If you want me to attend school, all you have to do is kiss me once” but… At that time she thinks, I will really kiss you !?