Some background:

Japan to open up Apple and Google app stores to competition (2023)

https://news.ycombinator.com/item?id=36368735

Japan enacts law to promote competition in smartphone app stores (2024)

https://news.ycombinator.com/item?id=40662176

iOS 26.2 to allow third-party app stores in Japan ahead of regulatory deadline (Nov 2025)

https://news.ycombinator.com/item?id=45822302