Mesudachi The Animation.

High school student Takumi Kusuki works as a wood seller in a remote village. One day, he receives a visit from Satsuki Satonaka, his tomboyish childhood friend who once excelled at basketball. When an accident ended her ambitions prematurely, Kusuki was the one who rescued Satsuki, earning him lifelong gratitude from her and her family. After discovering Kusuki's porn magazine collection, Satsuki teases him about it. But when her provocations do not elicit the desired response, she starts to act more lasciviously until Kusuki cannot resist her any longer.