I used Okayama airport(OKJ), on the west side of Japan, between Osaka and Hiroshima.
You can go there by using a Shuttle bus from Okayama station, it takes about 30 mins.
Mind you, as there are some international flights departing, it’s better to take the bus earlier.
How to connect to Wi-Fi
You can select ‘okayama_airport_free_Wi-Fi’ SSID.
After connecting the following page will be shown when opening your browser.
Then click(tap) “Access the internet here.”.
The page will be shown every 30 mins, which is a bit annoying.
Fill in your email address and accept the terms and conditions, then click(tap) “Confirm”.
Uploading : 2.62Mbps
Downloading : 0.88Mbps
As I mentioned above, you have to fill in your email address after 30 mins.
It will make you irritated…
There is a play space for kids at the 2nd floor, in front of the security gate.
Also there is a deck on the roof so you can see aeroplanes departing and landing.