Long time ago I read a manga about a pretty guy who was a cross-dresser. He obsessively was trying to emulate a girl he like. He was cached by heroine. She also had some problems, don't remember what kind of problems. In later chapters they had sex with him in cross-dress. She was jealous about the girl he was emulating. I think they later also did it without cross-dressing once they ware sure of their feelings. Yes they fell in love.

It centrally was not a comedy, more like heavy drama.

Also If you know any hetero romance with cross-dressing male lead give me a title. I only read the one I'm talking about and "Senpai is an Otokonoko".

This one maybe?

Himegoto - Juukyuusai no Seifuku

"The world is a dangerous place to live, not because of the people who are evil, but because of the people who don't do anything about it." - Albert Einstein

'Usotsuki Lily' has a cross-dressing male lead. It is a comedy (/gag) though.

...Hop!

yuri_shibuya Thank you, this is the one!
Also I am super surprised that this is a Seinen.