A rail company is offering one lucky couple the chance to get married aboard one of Tokyo's busiest commuter trains as it encircles the Japanese capital, it said Tuesday.

East Japan Railway (JR East) said it wanted to find a couple who would like to tie the knot aboard the usually heaving Yamanote Line, in the company of up to 120 friends and family.

“We expect applications from couples who are somewhat attached to the Yamanote line, including those who live nearby,” said JR East spokesman Yoichi Suzuki. “But they need not necessarily be rail fans.”

Guests will have exclusive use of the 11-car train, which normally carries around 1,000 tightly-packed commuters.

The train will take an hour to travel the around the 35-kilometre Yamanote line, stopping at all 29 stations but not opening its doors.

The nature of the journey will pose one possible challenge—there is no toilet aboard.

“The guests will be warned well in advance. I think this is all the same for ordinary weddings,” said Suzuki.

The event has officially been planned to mark the 50th year that Yamanote line trains have been painted yellow-green.

The ceremony has to be held on October 14, the 141st anniversary of Japan's railways coming into operation.

JR East is accepting applications for the next three weeks.

The winning couple can arrange the ceremony as they wish but must host and pay for the ensuing wedding reception at a hotel run by the firm.AFP

The nature of the journey will pose one possible challenge—there is no toilet aboard