Mijuku Kajitsu

Sonoko and Shou are childhood friends. One day he suddenly asks Sonoko out. He tries to kiss her and she tells him it's too soon, she then remembers a time in the past when they saw a movie together and learnt that a kiss is something special between two people, which makes her wait. Sonoko forgets something in the classroom and encounters a guy who demands she give him her body and he kisses her. (from Onigiri Gakuen)