American Fan:
Oh, I don't know if that's good or bad...cuz doesn't Mr. Sunshine have a sad ending? I won't even bother watching Gu Family Book if it's not a HE.
I like all the tags you mention though.
It's a BE but it was also beautifully filming and wrapped. It'd be a regret not watching.
You could also try The Disguiser.
The theme is quite similar.
About a young man who joined a secret agent (communist party, if I remember right) against Japan. He lied to his sister who owned some bussiness, and his brother who worked for Japan company. But there's a cool plot twist
And for some sweet romance, you could try ongoing drama My Cherie Amour.
It's a romantic story about a rich and pretty woman who's in search for the one and a mature and kind man who want to set up her with his younger brother. The clothes and buildings adapted European style. Very pretty.