Japan has a radically different profile when it comes to three important areas of 5G deployment: the allocation of frequencies, the management of the Huawei risk, and the national industry solutions.
This agreement between operators and the government made it easier for Japan to focus on equipment solutions without having to manage high-risk vendors. With regards to Huawei, Japan is politely enforcing a de facto ban without ever using the word. This approach differs from the US policy in that it escapes open confrontation with China.
Therefore, Japanese telecommunication operators overall do not suffer from the path-dependence constraints that several European telcos may experience during the first phase of deployment of non-standalone 5G, basically an improvement of the existing 4G core and radio access network.