So about the incest
Is it real incest like is the mom and sis really mom and sis for the mc or is it like we control someone else's body but are a 30 year old dude?
Like if the man died and got into another body then will he retain all the past experiences and become that actual person or not?
Asking this because I want to see if there are MC's reaction and struggles to the incest
No, it's real incest. (Ofc, you need to have patch from the Lewdpatcher link.) Molly is the mother and Rin / Lin are twins who are the MC's real sisters.
I can't even remember now, but I think Molly had been married and had the MC and then was married again and had the twins. She's not married now, so a single mom raising children fathered by different people. (The twins are Asian in ethnicity, whereas the MC is Caucasian.) This is all based on appearance, since I don't remember anything specified in the game itself. It might have been, but I can't recall it for sure. However, they are all for sure Molly's kids and related (half-brother and half-sisters).