a alicexreimu is fine too, but why does everyone need the human touhous to die huh? couldn't we just make some magic thing to make them live longer? Reimu becomes a buddha goddess, Marisa becomes a real witch, Sanae really is a living goddess, and Sakuya can control her time. Either that or the Erin-moon-species theory.
So after reimu has passed away, later when Alice past away they will be reunited in heaven just like in post #643577. Anyway the Moral lesson here is Cherish you precious time with your loved one(especially the oldest one) so when they will leave this world with "thank you" written on their face. (I regretted not being able to be side of my late grandma when she passed away)
After seeing this, It made me remember how precious life is. Life can only be made if something has to pass away. Sad but that's how it is. LIFE truly is Beautiful.