Japanese Citizenship?

I'm 23 years old, and I was born in the US, but my father is a Japanese citizen, he was born and raised there, but has since moved to the US, although he did retain his Japanese citizenship. Anyway, I was wondering if I'm eligble to obtain Japanese citizenship? I've heard I was supposed to apply for it before I turned 18, and some say 21, but if this is the case, isn't there some legal loophole that would allow me to obtain my citizenship? I'm willing to hire an immigration attourney, but I want to find out what my chances are first and what the procedures would be. Thanks.

My sources say no.

Most of what I read pertained to dual nationality but you haven't acquired Japanese yet. I don't know if you can still get it due to your age (1 year past the cutoff to chose which citizen you want to be as Japanese do not allow dual nationality) but you may be able to get a visa to stay in Japan longer than a tourist and do work. Have your father talk to the Japanese Consulate closest to you. Japanese Citizenship is passed paternally so you're lucky it's your father not your mother. You have to get on the family koseki (http://en.wikipedia.org/wiki/Koseki) to be a citizen. That comes from Japan and you have to have a Japanese address (just pick some relative like your father's jikka, permanent residence, parents' home).