Also this:
View attachment 2764421
That's a common recurring theme in happy events. Of course, could just be a funny thing to say, but Tsuneyo is becoming the most sus character in this game to me
Tsuneyo can also see shadowy figures, be called during a reset, easily understand the resets, and recall memories she wasn't around for.
Not to mention: Tsuneyo can talk to birds like Sensei, apparently has a thing for Whales:
which Amy recently mentioned:
(Whales being related to Saki, Sensei's mom), casually noticed that Ayane acted differently after she survived the roof, and has an at least implied relation to the wire god, trees, and Sensei's son, Noodles.
It's probably nothing though: