Mujikaku na Osananajimi to Kyoumi Honi de Yatte Mitara 3

Hiroki had been having sex with his childhood friend Meiko purely out of curiosity, escalating their purely physical relationship further and further. But his unconsciously growing possessiveness ended up hurting Meiko, driving a painful wedge between them. Then one day, he witnesses her walking home after school with another boy from their class... Overwhelmed with self-blame and half-resigned to losing her, Hiroki still can't bear it. He ends up chasing after Meiko when she goes to the summer festival...