When I first came across this, I wasn't expecting anything good. It does, after all, have the lowest rating of anything for this year's Madness Day. I was very pleasantly surprised to find something great here! It certainly got better. I believe this is a reference to "Touhou". I've never played those games, but I know how popular they are.
I don't see a pie. It was great to include all these great characters and moments from the series. Oh, and the music is nice too. It's more pleasant than most Madness flashes. Again, Happy Madness Day 2016!