A festival... I think I must have, because I know Lumine mentioned returning to Inazuma for a festival that I don't remember. And everything else about our journeys have been the same so far.

[Which makes for a pretty handy cheat-sheet, in spite of the existential dread brought on by overthinking why that's the case.]

What sort of festival is it? Maybe... if you talk about it, it might trigger a memory?