The festival could be originated from a Rakugo (a comic story) “Meguro no sanma” which is one of the classic in a genre of narrative art. Sanma is a cheap fish for masses and simply grilled is the best way to eat. The festival organizer offers 7,000 pieces for comers for free.
The venue is around JR and Tokyo Metro Meguro stations
http://www.enjoytokyo.jp/shopping/event/363237/
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