inkou karen doukoukai

Airi has just moved to a new school. She has a friendly personality and makes friends soon. But, there is one student she never meets. It's Rikka. She doesn't come to school often. One day, Rikka comes to school, and Airi is surprised to see her pretty face. After school, Airi goes to a sick-room and sees Rikka having sex with a male student...!