A Parallel World With a 1:39 Male to Female Ratio Is Unexpectedly Normal - Vol. 1 Ch. 76

[DaBoySwag77]

Yandere mom is best mom. She will go out of her way to out compete with the annoying gal only to make her son happy. But, since it plays in a perfect world -> The rivality will be decided through steamy rough handholding

 

[HoangDinh]

Mind break

 

[JethroBodine]

Ok, important information: the mother is 35. the big sis is between 18-20, so she conceived her between 15-17. So, high chance that in this world, there is a mandatory program for high school girls to get pregnant in their school days (the sister probably couldn't get pregnant by insemination). And there is probably a state program for periodic insemination to boost population grown (and chance to generate a male).

Some of this was covered in Chapter 18. The mother was 17 when she had Sumire. It's not mandatory for girls to get pregnant, in fact they have to enroll in a school to have kids although it is subsidized by the government. And it's not that Sumire can't get pregnant, she just wants Sou's kid not some random stranger.