Darling wa Namamono ni Tsuki

Setsuko, a daughter of a transsexual man who runs a cross-dressing host bar, meets, falls in love with and then marries the handsome Dr. Tanabe. Tanabe is normal, quiet and highly skilled at everything, while Setsuko is wildly different. Most of the series is comprised of the couple struggling first to have and then maintain their sex life and love each other. (This is definitely a series for 18+ however.)

(Source: Anime News Network)