When you first time visit to Japan, you would have no ideas about Japanese festival unless you had a lot of chances to know about Japanese culture.
There are innumerable festivals exist from a long times ago in Japan, and each festival has uniquely relate to identity of Japanese spirit.
It tell us only about traditional Japanese culture, but also those festival are consecrate beautiful ceremony for god in the nature.
You may know that you can feel more traditional Japanese culture in Kyoto.This event is a typical popular event especially Kyoto in Japan.
This festival has started from 869(Heian period) as wishes to recover for sickness people by plagues.
So, a shinto priest Torabe Hiromaro started pray that standing 66 long halberds which relate to a number of Japanese states at the time, and carry a portable shrine to Sinsen-En(a Japanese garden for an empire) was a primal reason as the event.
In this event, you can feel the dynamic and energetic shout and it would make you change different feeling about an expression of Japanese character. (Because many people think usually Japanese are quiet, but it is not true:)
Japanese notation：祇園祭り @京都
Tenjin festivals exists many places in tenman-gu shrines in each states of Japan. Those shrine was usually built for Michizane Sugawarano(845-903) who was honored as a god of study still now. But, this Tenjin Festival in Osaka is a well know as one of biggest event in summer in Japan. The event starts from the end of June until July 25th for almost one month. At the last day in the festival, you can see fireworks over the Okawa River.
Japanese notation：天神祭 @大阪
Kanda festival has been famous since Edo period as an auspicious event in Kanda shrine in Tokyo. At the time, floats were brought to celebrate the festival but now, it was changed to a portable shrine. The characteristic of Kanda festival is some huge objects such as ogres and catfish which are a symbol of myth(Shuten Doji). Those items are carried by many people in the long line through Kanda city in Tokyo and finally, they arrive in Kanda shrine. The event is held the middle of May every year.
Japanese notation：神田祭 @東京