Bon, together with New Year’s, is a representative traditional annual event in Japan. Whereas New Year’s is a Shinto celebration welcoming the Gods, Bon is a Buddhist rite. In the old, lunar calendar it was celebrated from the 13th to the15th of the seventh month, but it is widely cerebrated from August 13 to 15.
It is believed that about this time the souls of our ancestors come back home to get together with our family and go back again to their world. So to welcome them, the house and everything in it are cleaned, and Mukaebi (Welcoming fires) are lit in front the house. In the house, a bon alter is also set up to welcome them with various offerings like vegetables, fruit and rice, etc. Then for the visiting souls to go home, fires (Okuribi/Send off fires) are lit again.
Many Japanese companies and offices are closed from several days before or until several days after Bon as a summer vacation. People and families living in the cities commonly return to their hometowns to participate in bon festivals. So at this time, transportation facilities are jammed with families and people.