Tōrō nagashi ( 灯籠流し or 灯篭流し) is a Japanese ritual usually performed as part of the Festival of the Dead – O-bon (お盆) or Bon – in summer but also in connection to various other important events. In the ceremony people set lit paper lanterns afloat on a river or on the ocean, simbolizing the souls of the deceased returning to the afterlife. According to traditional Japanese believe, all life comes from the water. The ritual is however not unique to Japan, it is also performed in various forms in China, Korea and Hawaii.
In Richard L. Parry’s book “Ghosts of the Tsunami” one of the interviewees makes a connection between the ritual and the destruction of the town Naburi during the tsunami in 2011:
“An old fisherman named Yuichiro Kamiyama had moored his boat and gone about the houses, chivvying the villagers up the steep hill. From there, they watched the water withdrawing from the harbour, and returning unstoppably to overwhelm first the sea wall, then the road and then the alleys dividing the wooden houses, until it lifted them up and spun them around on its frothing surface. The water rose and rose through the pines on the hillside towards the spot where the dumbfounded villagers were watching. A few feet below where they crouched, it slowed and withdrew.
The sight reminded Kamiyama of the summer Festival of the Dead, when illuminated paper lanterns are set adrift on the tide to guide the spirits back across to the far world. ‘The houses receded all together, along with the sea,’ he said. “They were all in a row, like the festival lanterns, floating out over the sea wall. And the electricity poles too, with the wires between them. Those wires are strong — they didn’t break. They were all taken back intact into the sea. Perhaps I shouldn’t say so, but it was beautiful.’”
from: Parry, Ghosts of the Tsunami. (2017), pp 109
see also this post.