wanted adress shop, convention in japan

Hi,

I think soon of going to Tokyo and I will have wanted to know if you know some good addresses shops which sell cellulos. In the same way, one my spoken about a convention which is held 2 times yearly and which put together many collectors of cellulos, could you say to me when it is held and if possible its name? . Are there other conventions of cellulos in Japan or elsewhere?.
Thank you very much for your answer
In a friendly way

Maroin