I like the idea of our thoughts on this game. {how do I put spoiler around my post?}
Anyway, here is my take on this:
There is no real back stories of Marie and her three children. I really wish there was one. Only snippet of a story you get is from the driver at the beginning of the game where he says little bit about the Mamya family's history and how they were cruel to the locals and that they have lot of incest going on throughout the generation (well since 1913). I wish there was a back story on Marie and her "husbands" and who exactly these people were. There are multiple pictures of royal looking men throughout the mansions that you can see in the background, as well. However, one can clearly surmise that her three children are from three different father. Marika is apparently deformed, which indicates she is the product of incest (Marie's father or father-in-law is the father perhaps?), Marisa is from another father (most likely one of those rich guy who came to the mansion for the party). Even in the party Marisa dresses up as a "loli" character to attract these guys (Ojisama or uncles). And finally, the son of Marie, who has close resemblance to her, but she wind up having sex with him, possibly as early as he can remember. The father of this kid is probably the real husband Marie is referring to when she says that after the husband died, she has to take care of her children. She's often time seen with her wedding ring on her ring finger. Because of the three children are drawn differently, this is a logical conclusion. She also says that she swallowed semen from hundreds of men, which means she has a very debauchery and slutty past.
I wish Mikako also had a back story. Mikako's son, Makoto seems like he is from a different father, as well. He has blonde hair and blue eyes but both Mikako and her husband don't have blonde hair. Mikako claims that her husband is the only man she is ever been with, but I am sure when Sei drew these characters, he probably didn't have their genetics in mind. I am probably over-analyzing it but again I wish there was some kinda background stories behind these two characters to learn more about their past. I know Marie is definitely fucked up and possibly had or forced to be this sadistic, which is why she applies her methods on everyone. It seems like she was trained sexually and most likely forced to do things the way she does with everyone else in this game. Most likely three of her children are forced produced, as well or probably not even her children (except the son, who is definitely takes after her looks) but I digress.
Anyway, if you ask me, I think Marie is the best character in this game because of her personalities and the dominant effect she has over everyone. She is the anti-hero of this game. She is the joker from the Dark Knight...add a little chaos to a normal life, and you have a perfect blend for destruction. You see, motives are rarely unselfish. We do things (anything) because it is a necessary part of our lives. We have reasons for every aspect of our actions. We breath because we need it to survive. We wake up in the morning at specific time because we may have to go to work or we may have to take our kids to schools. We watch TV for entertainments. We have friends because we don't want to be alone. Everything that we do in our lives...every aspect or moments in each seconds of our lives have purposes and are driven through motivations or reasons.
Similarly, in the game Mitari chose to remain in the mansion (permitting you flow through with the story instead of ending it prematurely) is because her brother is ill and she must do anything to save him. The main protagonist remains in the mansion because ultimately he wants a car the most quickest way possible and this job will provide it. Sachie stays because she is greedy. Mikako and her son stays because her husband fucked up big time and can't pay back the money he owes. Everyone has their reasons to stay, be it forced or otherwise.
I believe that this gives an opportunity for Marie to test her sadistic view points on these people by experimentation, which is why she keeps doing those training throughout the game. She wants to see how far she can push these people to break their spirits. Granted that she says she was preparing them for the party but toward the end of the game, she mentions few things like giving them hopes and dreams and telling them that they have great futures ahead of them and that they won't ever be alone because now that they have discovered their inner sexual fantasies, they'll get through life very efficiently.
I mean it's like in the movie Saw, where the Jigsaw killer never kills anyone but forced them to an ultimate stale mate situation where the victims themselves wind up taking their own lives. What does it take to push a person so far at the edge that he is ready to commit the most heinous crimes or most implausible or improbable thing possible? The idea here is very similar to psycho-social studies done to test the theory behind Adolf Hitler's SS soldiers and their absolute loyalties. How can an authoritative figure have absolute control over a subordinate through simple commands? To kill for greater goods?
From the game, you have the option to get to the best ending by choosing few options and avoiding few others. It is you who must choose wisely. They did not bring this to a broader detail but Sachie pointed out to the main protagonist several times that the servant must do whatever their master commands. That's the only test and if they pass this and go through whatever they're ordered to do, then easy 4 million yens are theirs to grab. Think about it! In the interview, Marie humiliates both characters because that was the responsibilities of the position. She even mentions in the interview. She knows that everyone has perverted side in personalities. She just helps them discover it. She repeatedly asks them how many time they masturbate. If these characters were innocent and haven't a clue what masturbation is, then that would have turned in to a different form of gameplay. But no, each character admittedly mentions that they masturbate several times a week. The main protagonist says he masturbates 6-7 times a day sometimes. They discover their own inner sexual deviant and fantasies throughout the game.
The point is no one is innocent in this game. Everyone has their own agendas and perverted fantasy that Marie knows how to fulfill or explore. She just gives that little push and they all wind up exploring that. However, if these characters defy these and the consequences usually end up being severe. But the punishment is not killing directly but sexually torturing them. If they listens and goes through with their contract and stay in the mansion within the time they are supposed to, then you head straight to a good end. That's all Marie wanted. She wanted an absolute allegiance without any questions and just follow through. She does not kill anybody unless they were needed to be killed, for instance, the Mikako's husband. He was given the ultimatum but he didn't take it seriously to provide the money he owes. Again I wish I knew more about this story rather than assuming it ourselves because most likely there is some form of extortion going on here.
Anyway, there is no doubt that Marie has multiple personality and one of them being a good person, which is where she helps Mitari's brother to get the transplant. But later we find out that some of these organs might be coming from human trafficking or murdering (Mikako's husband being one). She is good and bad at the same time but her extreme perverted nature mostly gives her a bad rap throughout the game because her desires are driven through extreme sexual appetite. Because of her such sadistic nature and she has extreme sexual desires, she try to explore these with others to see if these people also have such tastes.
These tests aren't limited to her children, either. The children goes through the same form of torture. For example, Marisa freaked out when she started to grow little pubic hair because she knows she will be punished if Marie sees those pubes. She explains why her son is in to MILF, too. It is because she could not breast feed him when he was a child. He was breast fed by the mature servants, and this is how her son got the taste of old women. There are plenty of dialogues throughout the game explains why these characters are what they are but these dialogues do not explain clearly, though. They just hint lot of these through rhetoric or presumption. I guess that's why it is a game because the audience will reach to their own conclusions. I think this was one of the best game because of how fantastically every aspect of human perversion was explored through different fetishes. This is why I think Marie is the best anti-hero character in this game as she isn't a good person but she isn't bad either unless you force her to become one.
