Let me nitpick a bit.
To start. Satoko says he's honest. He lied about having to see his grandma and ditching the party, a party that was almost explicitly to have him be with his classmates. Whatever.
The rabbits. The student named Nat was in his class when he was in elementary school. Yet she has the rabbits now. How? Why? The snow only happened last year, well after Mashuu graduated from elementary school. The only possible explanation is that maybe Nat has a younger sibling or something like Mashuu, but we don't see any hint of that. The author was trying to be like herp derp, let's tie this together with this even though I haven't explained it enough.
And then finally, there's Mashuu's younger brother. Yeah, too easy. He's easily the one to hate here.