For foreigners, Japanese anime is one of the most common triggers to start earning their interests in Japan. There is an annual event called AnimeJapan where various kinds of anime fans, from beginners to the core ones, get gathered and widen their knowledge and community on anime. The last one was held in Tokyo Big Sight Convention Center in March 2015. The city holds the event changes every year so you should definitely keep an eye out for the news and updates if you're interested in attending.