100% Yumemi... What I wonder is if she is Yumemi's herself or not... We never know how the world traveling worked, she could have been from this future all along when she first reached Gensokyou
I was so eager to find out how the world works that I would rummage though books of physics in my futon. Looking at you two really takes me back.I was full of curiosity and vigor just like the two of you when I was a kid......
