[sarasi]

Both Omoide Yokocho and the area under the tracks in Yurakucho are known for yakitori- take your pick. I would say the Yurakucho area is more family friendly though, Omoide Yokocho (also known as Shomben Yokocho) can get a bit rough late at night as far as having very drunk people everywhere.

Don't expect to find anywhere in Tokyo with a lot of yatais/yatai style food unless there is a festival on- the Hakata yatais are famous because you don't find the same thing elsewhere in Japan, although I believe Osaka has some food alleys which could be considered similar- a look at online travel guides for Osaka should help you track the area down if you're thinking of going to Osaka.