Ten years after the tsunami hit the eastern end of Japan’s main island of Honshu survivors and relatives of those who died will be remembering the dead at Shinto shrines and other memorial services across the Tōhoku region.
The devastating tsunami suddenly took the lives of thousands of people, including children, who were going about their daily lives on a cold but ordinary day in the early spring.
Among those who died were 70 pupils and 10 teachers at Okawa Elementary School in Ishinomaki.
In the months following the disaster Ishinomaki was at the epicentre of supernatural phenomena, including ghost sightings.
Shuji Okuno, a journalist and author, travelled to Ishinomaki after the tsunami to document supernatural experiences, which varied from a couple whose dead child haunted his toys, to residents being visited by soaking wet strangers late at night.
But the most common were reports of “ghost passengers” from taxi drivers.
In one report a taxi driver picked up a young man wearing a thick winter’s coat on a hot day in August 2011. He drove him a long way and when they reached his destination it was after dark. But when the driver turned round to get the fare the passenger had vanished into thin air.
Mr Okuno told the Netflix documentary Unsolved Mysteries: "In all of these cases the meters would continue to log their travels, giving us evidence of these ghostly phenomena."
He said the drivers would usually end up paying the fares but he added: "Many taxi drivers had experienced the loss of their own families to the tsunami so they said they would welcome the ghost passengers with open arms if they needed a ride again."
Barri Ghai, a professional paranormal investigator and presenter of TV show Help My House Is Haunted, said: "I would expect there would naturally be an increase in ghost sightings or phenomena due to the sudden way people lost their lives."
He explained: "When a person dies in sudden circumstances often their consciousness or spirit doesn’t realise that they have died. The spirit becomes confused and often will carry on in a manner they may have been used to."
Mr Ghai said the 2011 tsunami may have left an “emotional imprint” on the land in the Tohoku region.
"This residual energy may be released sporadically or at specific times when environmental conditions are just right, playing over the last moments for some on a loop," Mr Ghai told Sputnik.
He said the taxi drivers may have been picking up ghost passengers who were "experiencing the repeating actions of those who just don’t realise they have gone."
But Kiyoshi Kanebishi, a professor of sociology at Tohoku Gakuin University in Sendai and the author of a book on post-disaster spirituality, said he had his own theory.
Professor Kanebishi told the Netflix documentary: "I think the presence of ghosts is a way for people to cope with Post-Traumatic Stress Disorder in their community."