Do people really care about your age in Japan? I just turned 40 this year, and you know what? Whoop di do!!! It's just a number, and I certainly don't act or look my age.
I've had numerous managers at potential teaching jobs bring up my age in an interview. I've had to tell them that my current supervisors are 10 - 15 years younger than me, and I treat them with the respect of their title. Age is never an issue for any of us.
I guess I've taken for granted the laws in the US that you can't refuse people based on age. Will this law ever exist in Japan?