Ok Tokyo tower got back to me. for november 1-3 they are willing to rent the whole of floors 3-5 for a vertical unconference. Should hold about 800 people. Not available to rent all the floors for the weekend of 4,5 but I think the space the smaller conference space fits about 200. 650,000 yen or about 50k usd at current rates. Told me they are likely to fill up fast so earlier is better.