Rental platforms like Airbnb are hoping for a boost from a new law coming into force next month in Japan ahead of an expected surge in demand for the 2020 Olympics, but experts warn it could actually hamper business in the short-term, reports AFP from Tokyo.

Currently anyone renting out a room risks falling foul of the law but short-term rentals will be legalised on June 15, clearing up a legal grey area.

But the new law also introduces fresh restrictions, dismaying many who rent out rooms to tourists via Airbnb or similar platforms. Would-be renters will have to register their lodgings with the authorities and the new law limits total overnight stays to 180 days per year. The new legislation allows local authorities to impose their own restrictions too.

The tourist-magnet of Kyoto, for example, has said it will only permit rentals in residential areas between mid-January and mid-March, the low season for tourist arrivals.

Jake Wilczynski, Airbnb spokesman for Asia-Pacific, told AFP the new laws are a “clear sign that Japan is buying in to the idea of short-term rentals for individuals”.

But many have cancelled reservations or simply taken their lodgings off the platform.

“Under the new law, Airbnb hosts will not be able to accommodate guests as easily as before. I hope this doesn’t put the bar too high for us,” 41-year-old Nobuhide Kaneda, who rents out a room in Tokyo, told AFP.

On an Airbnb discussion forum, an Australian host identifying herself as Narelle wrote: “I am... becoming frustrated that no one knows what is required.”

“I also feel the three-month timeframe to organise a notification number is unrealistic.”

Airbnb does not say how many properties on its platform already comply with the new laws but does not deny there have been some teething problems.

Wilczynski said the firm was “in the process of discussing the issue with the Japanese Tourism Agency”.

“We are waiting for instructions,” said the spokesman for Airbnb, which has informed its members of the legal changes.

Despite the new restrictions, there is a huge potential market for short-term rentals as the country gears up for Tokyo 2020 and the Rugby World Cup the previous year.