I've got this e-mail from someone whose child wanted to see Ultraman and the parent wants to please the child hence the parent scoured for information on Ultraman and I guess led him to this blog.
I want to help of course, though I would have love if the interaction not stop after I replied the e-mail so I'm putting my rather vague answer here. Also, my answer is based on our previous experience. I sure do not have the time to scour new information on Ultraman as my son has already outgrown this phase and the last visit we made that was Ultraman themed was in 2010. Also, I hope the parent read my posts on Ultraman over at this blog and I hope he did before sending me the e-mail. ^^
1) how long for the trips you reckon for us to cover the most and the best of ultraman
Define best of Ultraman. What are you looking for exactly? There is M78 Ultraman Park at GrinPa in Shizuoka, UltramanLand in Kyushu, Ultraman Stadium in Kanazawa and a smattering of shops selling Ultraman merchandises called M78 (if you are an Ultraman fan, you should know what M78 means, right?) around Japan. Tsuburaya Jungle is somewhere inconvenient to get to, in Osaka. Actually Ultraman Park, Ultramanland and Ultraman Stadium are rather inconvenient to get to, unless you are crazy enough to spend hours in trains and hopping in taxis and buses too, going to the middle of nowhere in Japan.
Do you want to see special exhibitions that might not interest a 3 year old?
By the way, did you read this before?
Also, do note that Ultraman in Japan are not even remotely aimed to non-Japanese. If you have done your research, you probably have heard about Ultraman Festival?
2) what's the budget like for 2 adults and 3 kids
depends on how much you are willing to spend on. This is very subjective.
3) how bout food ..is it easy to find halal foods while going around japan?
I wouldn't say easy if you are looking for specific Halal, muslim food. Be prepared to ask questions about how the food is prepared, that's my best advise. Be mindful about alcohol content in food too.
4) what's the best time to go there?
Anytime the airfares are cheap and you can get your leave approved. Any time is a great time to visit Japan. Well, maybe not during the Golden week. Research when is the time the whole of Japan goes on holiday and avoid that time.
5) what about "affordable" accomodation?
I have a hotel section on my sidebar. I harped about staying at one particular hotel chain over and over. But again, it may not suit you. There are plenty of affordable hotels in Japan that won't break the bank but it all depends on your preference.
6) can we survived without knowing any japanese language?
Yes, you can. Act nice. But be prepared to have headaches communicating and please, do not be arrogant when the Japanese you are asking help from doesn't speak any English. We've encoutered arrogant (not to mention rude) fellow tourists who think they are way above the locals just because they can talk in English. Japanese are nice people and will go at grat lenghts to assist you.
But if you can't understand simple Japanese at the very least, it's best to stay in big cities as opposed to traipsing around the countryside (where Ultraman Land and Stadium are located).
Anyway, unless you yourself is an absolute fanatic about Ultraman, my recommendation is to stick to Tokyo and Yokohama. Google up when Ultraman Festival is usually held. Clue : it's during Japan school holiday and it's hot. Another option is going to Kawasaki and head over to Ultraman Club there.
If your son wants to buy Ultraman toys, at all cost avoid M78 shops. Get them at a much cheaper price at Yodobashi Camera. Buy stuff at M78 shops the stuff you can't find at normal toy store.
I thank you for your attention.