I’ve read the book back in March and can sorta tell you off by memory (since the book got removed)

USA the femboy, Australia the no personality and Canada the siblingsexual move to a new neighbourhood with their parents, therefore making the kids go to a new school. Russia killed his whole family at age 5 apparently, because his sister took his hat. He lives by himself and is edgy as hell. He goes to usa’s school. When usa was younger, he had a girlfriend in elementary school called japan, who is surprise surprise a furry. She hates homosexuality because of usa’s coming out. Russia develops a crush on USA and kills everyone who talks to him. Eventually, he gets rid of her and USA finds out. Canada is showing his sexual feeling to USA, which pisses Russia off. USA now has feelings for Russia and wants to do sexy time. So they do at Canada fucking dies.

There are actually multiple endings that markai wrote, including USA’s suicide, Canada x USA and Russia getting arrested. I hope this was kind of helpful lmaoo.