お盆 (O-Bon or Lantern Festival) - 13-16 August

It is a Buddhist festival where it is believed that the spirits of ancestors come back to earth on those days. People light lanterns and put them in front of the houses in order for the spirits to find their way back home to their families. Afterwards, the lanterns are floated on the river to tell the spirits the way to the underworld. However, this act is forbidden in big cities to avoid pollution.