I can't get around my head how's this world even supposed to work. This is a society dominated by women, they prefer relationships with other women and look down on men, seeing them as weak but at the same time being wary of them, and yet somehow people have children. How does any of this work?
I thought it was explained by Hiro himself in chapter... 12? I kinda forgot, but in that chapter, he explains that in order to make children, the couple has to go through some procedure to perform the “magic kiss”—that way, they can become pregnant and have children, but I don't know if it makes both of them pregnant or just one of them.
And about women being wary of men... you mean when Hiro is fighting Grandma Sanjo and she looks scared, then you assumed all women are wary of men because of that?
The reason she's wary is because Sanjo Hiro was born into the main Sanjo family, and because of that, he has access to the “magic eye” more easily than Sanjo Rei, and its power is kinda crazy if you've read the light novel, but I won't spoil it. Because of that potential, people in the family are wary of him, since the requirement to become the family's leader is being able to unlock the magic eye. When Hiro shows his strength to the grandma, they become very wary of him.
As someone who has read the novel, even tho I still admit I might’ve missed something, I don’t see all women in the universe being wary of men except Hiro.
Edit: Ah, I think I understand where the confusion about “wary of men” came from. It's from that one panel where Lapis says she was told to be wary of men, right? Well, but just because men are said to be someone women should be wary of doesn't mean they're stronger than women. “Wary” here refers more to men's creepiness, like doing something perverted.
