O-Bon or Ura-Bon is the time of year ancestors are welcomed back to to the world of the living in some Buddist areas of the world, specifically Japan. The date actually differs because of the change from the lunar calendar to the Gregoarian calendar so different parts of Japan will actually celebrate at three different possible times. While well over 500 years old the festival is not always celebrated for the same reason today as it once was. Originally a time to honor those who have passed by cleaning the ancestral alters and providing offerings for the after life, many now take this as the time to reconect with family. Though the traditional dance, Bon Odori, is often still done. As a traditional folk dance it will be different in different parts of the country as well. But all the dances are to welcome the spirts from the other side to this world.
The festival concludes with Tōrō nagashi or lanterns being floated down the river to honor the dead. This is something that can also be done to honor those who have passed in general such as after the Tsunami of 2011.