With an increasing number of Japanese remaining single amid an absence of traditional matchmakers, one municipality is turning to big data to help people tie the knot.

More local governments are moving to help their residents get married, as the country's birthrate continues to fall.

In the western Japan prefecture of Ehime, a marriage promotion center in the city of Matsuyama started utilizing big data in March 2015 for its matchmaking system, in which members register their personal information and academic background.

The system now logs members' participation in matchmaking events and their browsing history on the website, enabling it to analyze preferences and recommend potential marital partners.

"Big data recommends types of people I have not considered before," said a woman in her 40s who was checking prospective marriage partners on a tablet device in early May. "It has expanded my options."

Following the introduction of big data, the chance of an individual agreeing to a potential suitor's request to meet has increased to 29 percent from 13 percent, resulting in 228 couples marrying between fiscal 2015 and 2016, according to the center.

From May this year, members can upload 10-second videos to enhance their profiles.

Big data is not the only reason for the center's success. Around 240 volunteers at the center, mostly married women in their 50s and 60s, also play a key role by providing advice to single people.

"It's always the volunteers who give a supportive push," said the center's secretary general Hirotake Iwamaru.

The success of the "Ehime method" of combining big data and volunteers has drawn attention and visitors from other parts of Japan.

But not all efforts by municipalities have proved fruitful.

Hyogo Prefecture set up a Tokyo branch of its matchmaking center in August 2015, hoping to help residents find partners in the capital who would then move to the prefecture on marriage.

Under its initial requirements to register with the Tokyo center, a member needed to be introduced by a Hyogo Prefecture resident or person working in the prefecture. But the center later allowed anyone to register.

It also keeps its annual registration fee at 5,000 yen, lower than private matchmaking services.

Despite such efforts, only around 110 people have registered at the center, with only 50 meetings arranged and one couple getting married, a sharp contrast with the 1,301 couples that the local government has helped to get married through its matchmaking service within the prefecture since 1999.

Meanwhile, the Tokyo metropolitan government has started its own matchmaking service, attracting around 3,000 people for its first event in March.

"We have a very low profile, so we intend to publicize more," a center official said.

A recently released government survey showed nearly one in every four men and one in every seven women remained unmarried as of age 50 in 2015.

The Japanese government has been implementing various measures to promote marriage, including subsidizing prefectural matchmaking efforts, with the aim of reversing the country's falling birthrate.

Still, there is debate among local governments about assuming the role of a matchmaker, a function once carried out by relatives, local communities and work colleagues.

"We need to be careful as it could be seen as imposing the specific value of marriage upon people," said a Kumamoto Prefecture government official.

"Since it pertains to an individual's views regarding life and values, it is hard to decide how far we should intervene," an official of the Niigata Prefecture government said.

Marriage service experts are calling for careful handling of the matter but say prefectures should continue to be involved.

"It is a private issue that requires care," said Yoko Itamoto, the head of People & Communities Network, adding, "Prefectural marriage support projects have yielded substantial results."