Can a Muslim be best friends with a polytheist?

Salaam. I have been friends with this person for a very long time. We get along so well and we understand each other. I knew from the beginning that he wasn't Muslim but he always knew I am Muslim. I was never sure what he was until a while ago he told me something that alluded to satanism...? Then later on he told me straight up that he is shinto. If you were to meet him you would never think he was any of these evil things. He is one of the nicest, most easy going people I have ever met. He is also pansexual but that never bothered me. Is it haram for me to be friends with him? He has never tried to force any of his beliefs on me, nor have I ever felt inclined to join him in what he believes. We hang out from time to time, we do things that normal friends do. My only worry is what I mentioned above.

I think, and it's really my opinion, that in this world, so much hate a separation is preached that when kindred spirits are found, they should not so easily be separated.  Only Allah can judge your friend. Have faith and conviction in your own beliefs and practice the best you can in the service of Allah. But I must stress to not give in to others will and desire for the separation of mankind. No good ever came of it.