Violent animal boys and girls

High School student Usami Touru bumped into his classmate Ayabe Reri, one day while taking a stroll. Ayabe is like an idol in their School. She is a usually a quiet and honest beautiful teenage girl. But by chance that night, Touru caught a glimpse of her skipping on top of a rail. The next day, Touru was asked by Ayabe to keep what he saw a secret. How will the relationship of such an unlikely couple play out?