TOKYO (Reuters) - Ceremonies to celebrate divorces have gained momentum in Japan after the massive March earthquake and tsunami, followed by an ongoing nuclear crisis, caused unhappy couples to reassess their lives.

The ceremony to mark a couple's transition to being single again costs 55,000 yen ($690), includes a buffet meal and culminates with the ritual smashing of their wedding rings with a gavel.

Tomoharu Saito, who took part in Tokyo with his wife Miki days before they were set to file for divorce, said crushing the rings felt cathartic.

"I did not think the ring could be crushed that easily, but it did," he said.

"I was shocked but at the same time, I feel it helped me make a clean break."

The ceremony also includes a "divorce dress," and Miki Saito chose a daisy-yellow summer dress. In Japan, daisies are believed to symbolize an "amicable or platonic relationship."

Designer Akiue Go said he created the dress with emphasis on the back for a specific reason.

"I designed this dress so the woman's back looks the most beautiful when she turns around and walks away," he said.

Hiroki Terai, a 31-year-old former salesman, spotted a gap in the market and pioneered the divorce ceremony two years ago. Since then, he's celebrated more than 80 breakups.

Requests for the ceremony have tripled since the March 11 9.0 magnitude quake set off a massive tsunami.

"The March 11 disaster made many couples rethink their priorities. Some found that work was a higher priority to them than family, and this helped people gain the confidence to decide on a divorce," Terai said.

"Those who want an amicable divorce are doing these ceremonies."

Miki Saito said the earthquake made her realize she wanted to be closer to her parents, who live in northeastern Japan in one of the areas badly affected by the quake.

"After the quake, my desire to go back and live with my parents grew stronger," she said.

Guest Hiroko Tada was present for both the beginning and the end of the Saitos' marriage.

"I'd say congratulations to the amicable divorce," she said.

"I could have never imagined this day would come because I was at their wedding, but since they did break up, this is one of the best ways to do it."

(Reporting by Hyun Oh; editing by Elaine Lies)

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