There has to be a level of chemistry for one. Sometimes similar interests, other times a peculiar aspect of their personality you like, or something as simple as an encounter will break the ice. I don't know every potential relationship between two individuals has varying factors that can influence the level of a potential bond.
I met my best friend in kindergarten when I pushed him down the slide and broke his arm (accident I swear, I wasn't looking and then I heard screams and a crash.) Then we saw we both liked Power Rangers when I walked him to the Nurses' office. Fourteen year later we're best of best friends
If you would like something to watch on Netflix, here you go = One Piece
Just let things happen. If you're meant to be friends with someone you'll meet again and again and do activities with each other and talk. You can't force or rush friendship.