After you install the app, the first thing you need to do is complete your user registration.
You need to be connected to the internet in order to register. To start using the app, you need to download information about things such as compatible Wi-Fi services, so it's better to register using your home Wi-Fi or in some other stable communications environment.

You can turn Wi-Fi ON from the device's Settings or Control Center. Please note that you will not be able to connect if Wi-Fi is OFF.

Go to a nearby Wi-Fi spot.
You can find the location of the nearest Wi-Fi spots using the the Wi-Fi spot map, or by using a supported Wi-Fi service.
You need to be connected to the internet to do this, so it's better to check the location of nearby Wi-Fi spots before you go out.

Once you reach a Wi-Fi spot, select the Wi-Fi to which you want to connect from "Wi-Fi" in your device's Settings. If "Japan Wi-Fi Auto-connect" appears below the network name, the Wi-Fi is supported by the app.
After you connect manually the first time, all subsequent Wi-Fi connections will be done automatically.

WOnce you connect to Wi-Fi, the app will automatically authenticate the free Wi-Fi service.

When you're connected to the internet, a notification will tell you to which Wi-Fi you are connected. Tap the notification to display the website of the Wi-Fi spot. Some information can only be seen on Wi-Fi, so be sure to check it while you're connected.

You can check information such as how many times you were connected, and which Wi-Fi you used, etc.
Have fun using Wi-Fi spots all across Japan.