Chapter thoughts
心底嫌そうな顔をした狼は大口を開け──今までに食べた皆を吐きだした。
Explanation: Werewolf digestion is very very slow.
ここに来て、泊まって、豪華な食事をとって、皆でゲームをして、伯爵のお茶やピアノの演奏を楽しんで、今日になった、と。そんな記憶に改変されている
I mean, apart from drinking tea with the Count, all of those did happen 
At the beginning of the chapter I thought it was something like “After the game, time was magically rolled back to the start, and then the game never happened.”, but I guess “magically meddling with everyone’s mind (and one smartphone)” works too. If demon werewolves can be real, this can be real too.
I think being the sole winner of this game while everyone else forgets isn’t something to envy though…
おれは少しだけ犬が苦手になった。
See! Trauma!!
それから、夢の中で伯爵の声を聞くこともあった。
Trauma!!!
はい! それじゃ今日は、副担任の先生を紹介しますね。」
Haha. Who’s it going to be? The werewolf, or the Count? 
Probably Imako, since ハヤト is the only one who remembers her.
──伯爵だった。
Huh.
「では、ルールを説明しよう。」
Hahahaha 
『君はおもしろい。』
『もっと私と遊ぼう。』
Oh no, ハヤト is cursed now 
Well, that explains the follow-up books.
じわりと背中に汗がにじんだ。
ただ、おびえはしなかった。
むしろ興奮していた。
もうあのときのおれじゃない。
──今度はおれがおまえをやっつけてやる。
Looks like someone got some
character growth
out of winning the game. Well, that, or an inclination for enjoying mortal danger.
Replies
I think she’s not so much a “werewolf who wants to eat people” as much as “a demon werewolf who wants to win against the Count”, with eating the kids perhaps as a bit of a bonus? I don’t remember the details of the book ハヤト found, but that’s my impression.
I think the whole setup to the game, i.e. the landslide and Imako leading them there, was all already magically induced to get the game going. It might also be possible in the same vain that Imako never really was at the camp and it was all part of setup magic.
Proper thoughts on the book will come later in the form of a review, but a few words now...
What I expected: A traitor game with intrigue and smart moments.
What I thought I got: Kids bumbling around (in an entertaining way) to a haphazard set of rules.
What it turned out to be: A puzzle to be solved!
So, it wasn’t what I expected and while I enjoyed it throughout, after a while I was pretty doubtful that it would come to a satisfying conclusion with the kids dropping like sheep and no werewolf clue in sight. But when it turned out to coherent and solveable my impression of it improved a lot again. I think it’s pretty good for a children’s book.
I think there’s a pretty good chance I’ll read the second book at least, but not with a book club because I don’t want to have to pace myself.
I really enjoyed the discussions here though. Thank you, everyone, for making this book club such a fun experience!