If anything it is likely that they use this technology to encourage the creation of more children.
We should also note that [I think, please correct me if I am wrong,] we have not been told about any men in the future, so this technology may also be used to compensate for a dramatic decrease in the population of men. Possibly due to some global cataclysm or yuri taking over the Earth or whatever
Damn, that's funny but the logic got it nailed good XD
We can just wait for them parents to shown up and see the truth.
Also, the sexy raincoat (?) fashion trend seems likely that the moral standard of their places are below what we are currently, further backing up your point of the low birth rate. From where I was, most noble lady (or any rich lady) would wear something that cover their body (like long sleeves or smth, bare minimum is short sleeve) just so that they won't end up getting kidnapped (my friend said). Even boys aren't being excluded ( ͡° ͜ʖ ͡°)
I mean, it's japan we're talking abt, so ofc the low birth rate seems kinda normal there, question is why the extreme development of easier "child creation"? While I think the low birth rate is part of developed country that life is so easy they can just work for themself and get all their needs and wants. It's also might be that they simply are not really care about children as an assessment of someone's relationship (like, them parents don't care if she had a child or not). It's like a world of desire, all you want is there without any consequences on the real world except your own mentality.
Like, damn. A nice durable n' comfy tent with mini A/C is HUGE! (You'll know when you've been camping out for 10+ days non-stop) and she just carry it then put it at the garden, forgetting abt it like it's nothing (I wish I were her T-T)