So I just completed the 6.9 version but I actually paid attention to all of the dialogue now, especially at the beginning, and something has been nagging at me. The MC's personality is strange. He's timid but then he suddenly gets the balls to do things that are kind of crazy, no matter the consequences. It's slightly bipolar or possibly even DID(Dissociative Identity Disorder) and it's starting to change my view of the story and everything. There's also the fact that the MC doesn't really seem all that beaten up about the situation he's in (His parent's having been murdered and all that), in fact when he's "grieving" it's almost like he's just playing a part.
I could go into a detailed explanation of everything that tipped me off, but honestly, I'm too lazy for that so I'm just going to come out and say it. I'm starting to think the MC is the one who killed his parents. Now that would be a twist, but if the MC is actually an intelligent psycho with a really nefarious ulterior motive like I'm starting to believe, it would make sense.
Basically how I'm thinking the story actually goes is like so:
MC somehow figures out about his Uncle and Aunt heading a crime family. A crime family his parents are key members in, and so that scene in some kind of cell at the beginning makes sense; the MC is torturing his parents for information so he can take over. He ends up learning that in the event of his parents' death he is to be looked after by his aunt and uncle. So he makes the perfect murder scene but stages it so that he could never be suspected, now he can investigate a way to take over said crime family from the inside but also at the top. He seems like a weak timid guy who couldn't do shit so automatically everyone underestimates him. Now he's also a perverted psycho so he thinks if he can seduce the members of his "family" he could use their help to overthrow the current head and take over, hence why it's a sex game. Of course, we are so focused on just getting in all the girls' panties that we fail to see the MC's plans. Then, in the end, he'll basically be the psycho who played all the other psychos, and we, the audience, will just be like

.
Only when everyone who the MC sees as a threat is dead will we realize what we've done. Of course, we won't give a shit because by then we would have fucked all the women and maybe even impregnated a few and the game will be over, but as adult game twists go, this game could definitely go down in history.