Some are so different that they do not even remotely resemble the original festival despite sharing the same name and date. There are also various local festivals (e.g. Tobata Gion) that are mostly unknown outside a given prefecture. It is commonly said that you will always find a festival somewhere in Japan.
Unlike most people in East Asia, Japanese people generally do not celebrate Chinese New Year (it having been supplanted by the Western New Year's Day in the late 19th century); although Chinese residents in Japan still do. In Yokohama Chinatown, Japan's biggest Chinatown, tourists from all over Japan come to enjoy the festival. And similarly the Nagasaki Lantern Festival is based in Nagasaki's Chinatown. See: Japanese New Year.
List of Festivals
Hanami (花見 )
Children's Day (子供の日 Kodomo-no-hi )
Tanabata (七夕 )
Bon Festival (盆 bon )
Lantern Floating (灯篭流し Tōrō Nagashi )
Cherry blossom Festival (七五三 Shichigosan )
Ōmisoka (大晦日 Ōmisoka )