Sonia's mom is the witch that saved the country. But no, actually she's the witch that plotted to seize control of the country. But no, she ACTUALLY planned the war out to mitigate the losses to the country. But no, she really worked with the prince to overthrow the evil king. But no, she actually just wanted to get rid of a rival and steal her research. But no, actually... (not gonna spoil this one and beyond)
they're not human (Sonia, Bill, Emelda, a lot of fathers, etc.)
I'll note that very early on Mine becomes extremely depressed and contemplated suicide, so for anyone bothered by that sort of stuff I'd avoid chapter 24. It's short and is done mostly to illustrate just how much of a toll Mine's constant failures have taken on her, but it's there.
Despite how things may seem early on, magic actually exists in the world. As the story progresses magic actually becomes a very important plot point. At first it's only important because it's the source of Mine's illness. But as more nobles get involved magic becomes increasingly relevant.
back in her world a second time terrorizing not-America.
Shedy fighting off a demon god as she flies around the world destroying saplings in order to get enough power to actually beat the demon god, followed by an evolution into Dea Ex Machina, a man-made goddess to protect the world. So literal deus ex machina, lol.
Shedy becomes a demon/god and lives the rest of her life protecting the world tree. She has no friends beyond a monkey and a slime and possibly the souls of the other secret alpha testers who she can't really talk to anyways. She's apparently happy, but I can't help but feel sad for her since her life now consists of sleeping until a threat appears for her to squash, followed by more sleeping. Not what I'd call a happy ending.
Chako/Yui, Chako is the gender bender in the tags and a guy as revealed at the end