Dear Friends Rina & Maki

There's the affectionless father and the overly affectionate mother, and then there's the beautiful 18 year old high schooler Rina.
"Friends are just meant to be used," is what Rina says when she is caught having sex with her friend's boyfriend. Rina has such a low opinion of friends, but when she is hospitalized her classmate from elementary school, Maki, appears before her, wanting to continue their free-of-charge friendship from long ago. In this day and age, just what is the meaning of friendship? A tale of friendship based on a true story, as retold by Yoshi (the same author as Deep Love).