Where can I find some of Japanese Yakuza clan's contact info/website (email)?

Question:

I can speak Japanese but it is hard to find the right websites (if yakuza even have them). Everyone in Japan knows where their offices are. I'm doing a research paper. Yomaguchi gumi, Sumiyoshi-kai for starters

Thank you,

Answer:

I don't think they will reveal their contact information that easily via the web. Unless you know someone personally in there, it will be difficult to gather information.