Worried about its declining birthrate and aging population, Ehime Prefecture in western Japan has been using big data to match people with potential partners. The prefecture's system recommends partners based on personal information registered with the marriage support center and the internet browsing history of the person looking for a mate. [...] Tochigi Prefecture, north of Tokyo, utilizes the same system. Katsuji Katayanagi of its marriage support center said, "Young people tend to leave things to others to do, so I think we need, occasionally, to ask big data to recommend partners." [...] In Saitama Prefecture, near Tokyo, where the system was introduced in 2018, 139 couples were married by the end of November last year. Some admit to meeting a person they might not have chosen on their own, with a prefectural official saying the system is "providing for a variety of encounters." Shiga Prefecture launched an online marriage support center in 2022, triggered by the coronavirus pandemic, and uses a system similar to the one adopted by Saitama. As of the end of January, 13 couples had decided to get married via the support center. Six of them were with partners introduced by AI.