I have a Japanese wifi only model and live in Japan. I check everyday for the update and it fails to find it. I did a factory reset, and still, nothing. I'm getting upset. Any ideas?
Maybe you can try turning the screen time out off plug it in with wifi on so it is active over night and see it maybe it picks it up. Just a shot in the dark but who knows.
If I go to Select App on Sony S main page it takes me to an en English page that has ICS 4.0.3 "now available " icon that you can click. Maybe no Japan counterpart but easy access for EN.