Darling wa Gaikokujin
 

I have read that this manga is also nice

How to "Read" Manga: Is He Turning Japanese?, known in Japan as Darling wa Gaikokujin (ダーリンは外国人, Dārin wa Gaikokujin?, literally "My Darling is a Foreigner") is a manga series written by Saori Oguri. The English subtitle of the Japanese editions of the first two entries is "My darling is ambidextrous."

The books are published by Media Factory, Incorporated in Japan and Digital Manga Publishing in North America [1].

The series is about Oguri's relationship with Tony László, an American writer of half-Hungarian half-Italian descent who lives in Tokyo.

Anyway I have also read that they are making it into a movie