The super erotic production group Ifi-Wo-Ka has turned the popular CG collection of the doujin circle Yorokobi no Kuni into an anime! rnOne day, the protagonist returns home and finds an unnatural hole in the wall of his room, and when he looks through the hole, he sees Sayaka masturbating. The next day, Sayaka musters up the courage to put his penis in her hole and starts licking it as mushrooms grow on the wall. Sayaka, who couldn't be honest with her brother, was able to have the creampie sex she had always wanted thanks to her hole... rnrn★SynopsisrnOne day, the protagonist returns home and discovers an unnatural hole in the wall of his room. Behind the hole is my sister Sayaka's room, curiosity