if you're in the mood for a seinen with a similar mood to mushishi, I'd recommend Fushigi na Shounen. It's only implied he's some sort of a god, though

Inugami It's not the main character but a character accompanying the main lead.

But in the end, close enough. Actually I can't really remember the whole story because I read it almost 3-4 years ago, but you may be interested in it.
Wagaya no Oinari-sama.
Kagamigami The main character is possessed by a God/spirit, does it count?
Mahou Tsukai Kurohime is interested, I second it.

You may want to try Unorthodox Love Interest in the tag as well.

Chinese Translator Accepting translation requests if the manga interests me!