Derfel, feel however you do about it, Coming of Age is a national holiday in Japan, and all across the nation there are city/town sponsored Coming of Age day celebrations. I have emceed one such event once, and let me tell you that people here do think it's something worth celebrating.
Deenax, what kind of questions are you interested in asking? I agree with Glenski that it would be helpful to be a little more specific.