Porn Game: UchiKano: Living With My Sister - Version 1.0 by Argonauts

Overview:
Tachibanaki Keisuke, a young man in his first year as a full-fledged member of society. While the company he works for is a small one, it's the job he always wanted to do and his life is pretty satisfactory. But even though he's both motivated and has much to aspire for, he's now living alone for the first time in his life, and it's becoming a bit exhausting. It's then that a certain thought crosses his mind...

"If only I had a girlfriend..."

One day, his younger sister Riho arrives at his doorstep. Both of their parents are sick with the Norovirus. With Riho's college exams coming up, her parents urge her to seek shelter at the protagonist's house. Riho has been aware of her brother as a member of the opposite gender for a long while. And with the two of them living together, these emotions only grow more intense. And Keisuke himself begins finding himself attracted to Riho as a woman...

Their relationship blossoms to something BEYOND BROTHER AND SISTER...

UchiKano: Living With My Sister - Version 1.0 by Argonauts game preview

online.