Hmmm, is this the one with story on the wiki? Where Reimu goes through a succession of lovers, before shacking up with a Wild Reimu...That's ultimately raped by Alice?
No, this one depicts a "happy" Reimu-Reimu couple, and then seems to show that one Reimu is sort of crazy-obsessed (she "convinced" Reimu's parents to accept their union by killing them), and the other one is sort of depressed and Stockholm-Syndromed, passively agreeing with whatever Reimu says, but clearly unhappy.
I'd need to read it more carefully to figure exactly what's what.