Japanese events and festivals are celebrated through out the country all year round, there are about 300,000 traditional festivals in Japan. The Japanese word for “festival” is “matsuri (祭り)”, in most cases each festival is sponsored by a local shrine or temple. Most of the Japanese festivals are celebrated over the weekend, big festivals like Sanja Matsuri, roads are usually closed to give way for the celebration.
If you happen to be roaming around Japan or Tokyo specifically, you can easily a spot Japanese events and festivals if you see processions which includes big and intricately designed floats. Of course, that also includes loud taiko drum beats and Japanese people chanting while they carry the traditional mikoshi.
Every season in Japan is accompanied by specific festivals for each area. Popular festivals are Takayama Spring Festival, Awa Odori Matsuri (Summer), Nagasaki Kunchi (Autumn) and a bunch of snow festivals in winter like Sapporo Snow Festival.