well like in all the votes we've had, Haruka and Mitsuki are tied
Mitsuki is just hot, her integrity is not as strong as Haruka's or Akane's. plus she is too paranoid. as for the sex thing, the only thing she will have done wrong is have sex with shinji (IF she does).
but, its not worth defending mitsuki over this, after all this poll is a matter of preference, any possible bias / morals / preconceptions can apply