I wanted to find a doujin based on its plot. I have already searched the tags (incest solemale solefemale -lolicon -shotacon) to no avail on nhentai and some other sites.
Plot : a lazy shut-in (hikikomori) sister don't want to go out of house and her brother urges her to go out by even playfully threatening her to rape her if she doesn't , at start he just make the sister do a blowjob and later they end up having sex , eventually the sister says she could let her brother do her everyday and never go out (a happy ending)

side note : i recommend 379921 if you haven't read it yet