Okay - I rewatched the entire run up to here, and have a bit better idea what’s going on.

There’s a scene in an earlier episode - I forget which now - in which another veteran mentions Candle Woods to Yuki, and says she heard that that was a bad one. But it doesn’t seem that she’s aware that Yuki was in it - she just refers to it as if it’s a landmark game - as if the history of the games can be divided between before Candle Woods and after Candle Woods.

The Tanuki and the notion that Tanuki’s lose to rabbits is from the folktalke Tachi Tachi Yama, in which a Tanuki tricks an old farmer couple into eating a stew made from their children. That doesn’t bode well for this game, and the fact that the rabbits have to survive for a week to win.

I still can’t find a reference to a folktale about rabbits and stumps. The closest I can find is a sort of sequel to the White Rabbit of Inaba in which the hero is trapped and dies in a split tree, which I guess might sort of count, but he’s not a rabbit - he’s the hero who saved the rabbit in the original story. I dunno…

I noticed in rewatching the series that in the early games, Yuki’s eyes are both blue, and it’s only later that they shift to heterochromatic - one blue and one gray. I suspected that this game might be the dividing line, and sure enough, there’s a scene at the beginning of this episode when they focus on Yuki’s eyes and they’re both blue, but then there’s another brief scene later in this episode that’s apparently after this game, when she’s sitting in a chair watching film of the game, and specifically of a conversation with her mentor, and in that one, her eyes are heterochromatic.

And as I also sort of suspected - during the scene when Yuki’s mentor is talking strategy with the rest of the serious veterans, they focus on her eyes closely enough to see that they are in fact gray.

The next episode is going to be brutal.