Natsu no Iinchou

It's the story of unrequited love for the class president, a girl who is always at the top of her class in both academics and sports and belongs to the rhythmic gymnastics club. My crush is the class president of the school. One afternoon after school, I save the class president from being assaulted by delinquents. And then... the class president and I transform into a lustful man and woman... [Translated from Getchu]