Visiting for 10 weeks (Tokyo)

Hello all,

I will be doing an internship in Tsukuba for 10 weeks this summer. I have never been to Japan, I don't speak Japanese, and I will be entirely by myself. I am not worried about safety so much as loneliness! I am naturally pretty introverted but I like to hang out with my friends at home, so I'd like to find people to socialize with in Japan too. Are there any expat groups in Tokyo that do activities together or something like that?

Thanks!