Boku no Kanojo wa Sasuga desu.

Hatsune is a high school boy who looks girlish, with doesn't seem "manly" at all. However, he has a beautiful girlfriend who is the envy of everyone, a lady who is smart and athletic! He is proud of his girlfriend, Takaya, who accomplishes everything so perfectly, but he gets a little down on himself because of their differences...? This is an intensely sweet coming-of-age romantic comedy about living with a wonderful and perfect girlfriend!

(Source: Manga Park, translated)