The number of private lodgings in Japan has increased eightfold since the law legalizing them took effect a year ago to relieve a shortage of hotel rooms in the wake of the inbound tourism boom, according to data released by the government.

There were 2,210 such minpaku lodgings when the law took effect on June 15, 2018, and the number had risen to 17,301 as of early June with nearly half of them offered in Tokyo and Osaka, according to the Japan Tourism Agency.

The data also show that the rapid expansion was driven by corporations diversifying into the private lodging business.

Around half of listed private lodgings in the country are operated by corporate bodies, according to the agency data.

Still, some experts say the minpaku business needs to be further deregulated as lobbying by the hotel industry has resulted in a cap on the number of days operators can offer their rooms, making it difficult for some to make profits.

According to the agency data, 982 establishments have been discontinued over the past year. Private lodgings can only operate 180 days a year.

Filtering out of illegally offered properties continues to be a challenge for local governments as operators are able to contact potential visitors directly through social media outlets.