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...