The steps are as follows:

1. In the store, click three, as follows. Before switching, you must first connect the mobile phone network to the country you want to switch to. For example, if you switch to Japan, the network must be connected to Japan. Because it is judged based on IP, it cannot be switched without connection.

2. Next, you need to click on the account, as follows.

3. Next, you need to click on Account Preferences, as shown below.

4. Click to add a credit card or debit card, as shown below.

5. Click Continue to switch your country region to Japan.

6. The effect after switching is as follows. The stores are all in Japan. Note that you can only switch once in a year, according to the official statement.