Ryuta and Maeko Kato end their six-year marriage not merely by signing a divorce agreement, but by inviting guests to a public separation ceremony.

The erstwhile husband and wife begin by mounting separate rickshaws on a blustery Saturday morning in Tokyo.

The atmosphere is almost funereal as the unhappy pair wend their way through the back streets of the capital's Asakusa district, within earshot of the tourist hordes praying for happiness at Sensoji temple.

Their three guests – two friends and a cousin – walk behind the rickshaws with their eyes lowered. Not a word is spoken.

The Katos are among a small, but growing, number of Japanese couples choosing to bring their union to a close at a public, and at times surreal, ceremony pioneered by "divorce planner" Hiroki Terai.

The 30-year-old, who goes about his work in the manner of a punctilious clergyman, brings the party to a halt at the "divorce mansion" – actually little more than a covered parking space next to a dilapidated building.

The tatty location is a deliberate choice, he says – a symbol of the disintegration of the couple's marriage.

Since conducting his first divorce ceremony in April 2009, Terai has presided over more than 60 separations and received 1,000 inquiries.

Business is brisk thanks in part to Japan's divorce rate, which has started to creep up since peaking in 2002. There were 253,353 divorces in Japan in 2009, according to the health and welfare ministry, almost four times the number 50 years ago.

The half-day "divorce tour" costs 55,000 yen (£410) per couple, with extra charges for bouquets of flowers and slide shows of the couple in happier times.

Bigger ceremonies, involving dozens of guests, are held at hotel function rooms usually reserved for wedding breakfasts.

"People have a ceremony when they get married, so why not for divorces, too?" Terai said, as Mr and Mrs Kato, seated back to back, ate lunch.

A short toast made with tea – to avert any alcohol-fuelled airings of dirty laundry in public – briefly breaks the silence.

"Some people, even after they're divorced, can't quite accept that they're no longer together. This gives them closure."

At the divorce venue, Terai offers guests a diplomatic explanation for the collapse of the Katos' marriage. They had drifted apart and, despite attempts to reconcile, "ended up feeling they were no longer part of each other's lives", he said.

After a few words from the Katos and from a representative of the guests, it is time for the couple to come together in a final act of catharsis: the smashing of the ring.

Somewhat awkwardly, they grip a single mallet and with a thud bring it down on the wedding band – actually a cheaper ring – squashing it on the second attempt, to half-hearted applause.

Though their separation has still to be finalised legally, the marriage is effectively over.

The damaged ring is placed in the mouth of a frog-shaped receptacle painted shocking pink, and the mallet – also adorned with a frog design – handed back to Terai.

The frog imagery is important: the creature is viewed as a harbinger of new beginnings, partly because its name in Japanese, kaeru, is a homonym for the verb meaning "change".

"I was surprised by how happy and relieved I felt when I brought the hammer down," said Mr Kato, 34, who initially had reservations about marking his divorce in public. "I could see the future ahead of me for the first time. It was like being reset to zero."

The couple, perhaps not surprisingly, had argued about where to get divorced – in Asakusa or on a pleasure boat in Tokyo Bay. Today, at least, their feelings are in synch.

"When I saw the broken ring, I knew it was over," Mrs Kato, 31, said. "Doing this in front of friends who attended our wedding might seem cruel, but at least it proves that we were willing to co-operate right to the end."

Any pretensions of harmony had all but disappeared by the time the party embarked on the final leg of the tour, a spot of sightseeing in Asakusa.

Several hours after beginning their new lives, supposedly cleansed of resentment, they had yet to exchange so much as a brief glance.