Kimi wa Yasashiku Netorareru The Animation

キミはやさしく寝取られる The Animation

Rio, Haruta's childhood friend who he's always had feelings for and her older brother, who he respect. Rio returns to her birthplace for the first time in a long time and goes to see her brother, who she has a crush on. And she's been forced to wear perverted underwear by her brother, who's become a completely different person from before, she's being made to have sex in the shade of a park... There's a relationship only Haruta doesn't know about between the two people he loves...