The boobs size difference compared to Reimu isn't big enough, yet Sanae's boobs are too big to be cute. That's a double loss to Reimu right there, Sanae.
Sanae, you are far more than just your beautiful luscious large breasts... As much as I am obsessed with big boobs I think your quirky nature is very endearing.
My boobs are bigger than Reimu-san's, so I must be cuter...