Thanks for the fantastic game!!! I was captivated and entertained the whole way through, more than worth the asking price. I'll tell my friends about it too!
**SPOILERS**
I wanted to post a comment here because of some hints that it felt like oriana was obviously dropping about her potential connection to the mastermind. I know she said that some clues might lead you astray if you make hasty assumptions, and i also know the timelines don't match up (given the comments about "decades") but some of oriana's reactions to things only make sense to me if she was the boy from the family as a child.
She's cagey and uncomfortable about the child's room and empty bedroom, has rather unique reactions to a certain dead body, was extremely timid in her early highschool years, seems to also realize the implication that the protagonist is also connected to the professor somehow... There's also the comments about her height and obviously her breast growth. There's also some resemblance in the art assets! I know a lot of this could technically be related to her recovering some timeline memories combined with her strong sense of justice over what the mastermind did to his son. The protagonist's innate desire to protect Ria also raises my eyebrow, though i do acknowledge this could be a very specific person's influence. There's a bunch more reasons why this theory makes sense to me but I won't list them exhaustively here.
Potentially the protagonist could also be the son, or especially the daughter. I like certain mysteries remaining unsolved of course, so feel free to decline to give any answers to this! I'll always have my own interpretations of events i can continue to develop as well, but it'd be fun to know if I picked up on anything purposeful.