About 1,200 mourners filled a hall to overflowing, with many standing outside a gate, for a ceremony organized by 170 priests in the northeastern town of Soma, where much of the coast remains buried in mountains of debris from the March 11 earthquake and tsunami.
Many carried framed photographs of lost loved ones, and wept. Some clutched wooden tablets containing Buddhist names assigned to the dead to help them find their way into their next phase of existence.
"There are so many still missing. There are people lost at the bottom of the sea who will never be found. But this is the day they become Buddhas. We pray for them all, and for all sentient brings," Buddhist priest Kojin Sato said.
Overall, the quake and tsunami is believed to have killed nearly 26,000 people, though only about 14,500 bodies have been found. Many likely were swept out to sea and will never be found.
Kiyoshi Sakurai fears that will be the case with his elder brother, missing since the disaster.
"It's very difficult because we couldn't have a proper funeral. But this gives us some feeling of closure," Sakurai said, clutching a blurry photo of his brother.
"It was comforting to have so many priests come to pray for our relatives. Maybe someday my brother will be found. Maybe not. But he has at least had this," he said.
Many Japanese share Buddhist beliefs with the native Japanese religion of Shinto, which worships spirits in nature and dead ancestors.
Virtually all rites related to death are Buddhist. In many Japanese schools of Buddhist thought, the dead wander near their homes for 49 days before heading into their next stage of existence on the 50th day.
The Dalai Lama, the spiritual leader of Tibetan Buddhists, was visiting Japan on Thursday and scheduled to join in another memorial in Tokyo later this week. Spokesmen for the religious leader said he had altered his schedule to be in Japan for the 49th day since the disaster.
Seven weeks after the magnitude-9.0 earthquake and tsunami struck, some 130,000 people are still living in about 2,500 shelters. The government has promised to build 30,000 temporary homes for them by the end of May and another 70,000 after that.
The head of the American Red Cross, wrapping up a four-day visit to Japan, said the $187 million it received in donations and pledges for Japanese tsunami relief is buying essential household appliances such as rice cookers for people living in temporary housing.
"The (power of the) ocean was just furious. Everything we saw was strewn in small pieces," she said in an interview with The Associated Press in Tokyo. "When you start walking around, you can see a doll or a kid's bicycle or a teacup. It just strikes home that this is so personal."
In Soma, Sato said that said local temples invited anyone to come to the ceremony and told the bereaved not to worry about dressing in black, since many people had lost their formal clothes. The priest added that instead of the usual gifts passed out after funerals, the bereaved were given bags with bottles of water, tea and soap -things that they might need in shelters or temporary housing.
The ceremony closed with a silent procession before an altar. The only sound was chanting and occasional weeping.