I'm pretty sure the twist on the Tale of the Bamboo Cutter is going to be similar to Touhou's mutation of it, where somehow Tsukasa got the elixir before they actually threw it away.
Plot twist : coincidentally Nasa stumble upon the elixir drop then with ease make un-immortal medicine balm for Tsukasa. Then they live happily ever after.
that's some important info for plot.
Her house was burned in the mountain, that granny took her in, she left for Nasa in 2yrs , how the hell did she know where he lived, (, that granny bought a mountain, also the moon stone tsukasa's
room had
plot twist: Kaguya from the story was actually a guy and it was Nasa who got reincarnated and Tsukasa was the emperor and she actually drank the elixir
at this point I don't know but I hope it completes what it need to do and then calls the series end. I don't want it to have a half ass ending without even looking over so many things it has left empty