Well, it's like this, the friend in question came to visit me and as it happened I had an anime soundtrack CD playing and he remarked on the music because the singing was not in English so I told him that it was a soundtrack from a Japanese animated series and as the PC was on I showed him some pictures I'd downloaded, this was before the days of DVDs and digital media, and he liked what he saw. So I suggested that he come round one Saturday and he could watch some of this anime thing to which he agreed. In the end we ended up spending all Saturday afternoon and evening watching anime, after which he was hooked! For several years after that we met up about once a week to watch anime and went to anime conventions together for several years, where he was spending as much on anime stuff as I was!
Sadly, other commitments mean that we can now only meet up a couple of times a year, but he's still interested in anime. He's also the only other person I've been able interest in anime.