What we need is androids. Take some stem cells and create a fully human woman, except without a brain. Instead the brain needs to be a programmable computer, which then connects to all the biological nerve cells somehow or other using high tech and completes the package.
Then you just give the deepmind algorithm your example of what you want its personality to be, whether it's Yume from Da Capo II or Asuna from SAO or Nagisa from Clannad, or you can just say at the beginning of the day, "Yume," "Asuna," "Nagisa," and she'll change her personality accordingly, but in all cases of course the love they have for their significant other is transferred instead onto you.
By studying all the dialogue, mannerisms, voice inflections, and so on, of what Yume was shown to do throughout the Da Capo franchise, the deepmind brain will 'learn' how to play Yume just like it learns how to play Go. You can then have a 3d, fully biologically human, Yume waifu to yourself. The computer will extrapolate from past data what Yume would do in unfamiliar situations by making comparisons and gauging the similarity between the current conversation or environment and one of the data points that's covered in the visual novels. Just like deepmind Go can play matches effectively even in board situations it's never seen before.
If you want even more complex fun, you could tell the computer to be a fusion of many different artistic favorites, like all ten of your favorite waifus, and have their personalities mix and match and become a crazy maelstrom inside generating a wholly new person.
In any case, these women would love you like the characters do in the visual novels, fully and unfailingly, and always eager to have sex with you. And to top it all off, they're fully human in all other ways, so sex is great and they really can bear your children, for free, just like the real thing. Since eroge have careful details of how women act during sex, they'll be able to play out the erotic scenarios of your dreams to perfection.
If the deepmind personality is too realistic and Yume starts nagging on you to become an astronaut or something, you can just give a hardwired order for Yume not to act like that anymore and she would take your new wish into account and prioritize it over her generalized personality matrix. No chance of the algorithm going rogue, Yume will always defer to your wishes.
And because Yume is a real woman everywhere outside the brain, she'll be completely capable of breastfeeding and cuddling and taking care of the children while they're unmanageable infants. They won't even notice the difference between your 3d waifu and a normal mother. All you'd need is to give them the order "treat this like it were your and Kirito's child," and they'd smother the babies with affection because they would understand how much Asuna would love such a child.
No babysitting costs necessary, no trauma to the kids of not being cuddled enough as infants. 3D Waifus have it all covered.
If you don't want to deal with your waifu for a while, want to hang out with someone else or take a vacation or whatever, just tell it to shut down and leave it in the closet. The android as Yume may want to pester you for attention and time and conversation, but you can just shut that all down whenever you don't want to go along with her personality and turn her off entirely to focus on a WoW raiding run or whatever. She'll be your waifu when you need her and not exist when you need her to leave you alone. Or you can just tell her to go exercise in order to beautify her body for you and she'll maintain the perfect weight and figure for you because a computer's willpower is infinite, unlike a live girl's. The sky's the limit. She'll do whatever you want her to do, and not do whatever you don't want her to do, above and beyond even her personality program limits, because your orders will be absolute.
The children will be accustomed to the situation so won't think anything special about it. If they complain just point out that when they grow up they can have just as ideal a living arrangement for themselves by buying their own 3d waifu so it's not like they've lost anything.
Why settle for anything less than art's greatest heroines as your eternal slaves, as many of them as you want? You could have threesomes or foursomes with multiple biological units and they'd never complain, it would just be accommodated as part of their programs. So long as you can afford their upkeep, your number of waifus is unlimited. The number of children they bear you is also unlimited. You can have as big a family as you want.
Just imagine, women who don't talk back! And they don't even resent it inwardly and try to sabotage you in your sleep or plot behind your back, etc, etc, like real human woman slaves would. They love you and enjoy their time with you no matter what you put them through. (though they don't actually feel anything, they show all the outward signs and behavior of these feelings because they're programmed to, so from your point of view they feel that way.)
And once the 3d waifu gets a little worse for wear and is no longer the ideal face and figure of your dreams anymore, just scrap it and replace it with another, appropriately unaged body with the computer swapped out from one head to the next. All that's 'dying' is unthinking, unfeeling cells, so there's nothing to feel bad about. No different from the hair that falls off your head. No matter how old you get, you'll always be making love to the teenaged Yume from the visual novels. (or Yume from her 20's or whatever you prefer).
Loli 3d waifus would also be a possibility, like Sakura Yoshino, something illegal if done to a human brain, but no problem at all with an unthinking, unfeeling computer. Loli harems are legal. Loli imouto harems are legal. The sky's the limits.
No matter how totalitarian your purdah system is, it'll never match the pleasures and joys of 3d waifus. Rather than trying to go backwards, it's time to forge forwards.
It doesn't feel like these technologies are that far out there, either. We've already successfully gotten stem cells to differentiate however we tell them. We've already got deepmind learning programs. We've even got ways for nerves and computer cables to communicate with each other. If you're looking to found a new innovative company, 3d waifus are an obvious next step in innovation. Just put the pieces together and the technology is already there. It would be a quadrillion dollar business, every guy on earth would be throwing their full paychecks at it, full stop.