Rin and Len discussion

Do you view Rin and Len as twins? If so, then how do you justify pairing them toghether?
(if you can't justify it, well, then you're just like me. :p)

If you don't view them as twins, what is their relationship, other than lovers?

I see them as twins because I have always seen them as twins so it freaks me out seeing them as lovers

I see them as twins in a movie. so fake lovers.