Beg all you want. The law is the law and interpretations of it are at one's own risk.
Agree and since this is an important issue for some readers on this forum, I would suggest that posters base their comments on an understanding of the actual law (which does not consist of statute alone) and/or advice from Japanese attorneys rather than on a cursory read of the statute.
Declaration of choice requires one to try to get rid of foreign nationality.
Yes. It requires you to try but not to actually get rid of foreign citizenship. And for dual nationals, there is no legal method or sanction under Japanese law for either forcing you to renounce foreign citizenship or for revoking Japanese citizenship unless you accept a position or employment with a foreign government agency or refuse to sign a (non-binding) declaration of choice.
Legal mechanism is spelled it in Art. 15.
Yes, and the mechanisms spelled out under Japanese law have no actual impact on foreign citizenship. Those are determined by the laws of the relevant country.
And as you will note a key component of renunciation is that it must be voluntary. The US courts and agencies have determined that compulsion under foreign law (unless you are applying for foreign nationality after the age of 18) by definition can NOT be voluntary and therefore you can not renounce citizenship to comply with Article 14 of the Japanese Nationality Act unless you perjure yourself. In practice consular officers at the US Embassy in Tokyo will automatically ask you if you are renouncing US citizenship in order to comply with Japanese law on dual nationals and send you straight home if you answer in the affirmative.
Again thinking one knows better is fine, but we must also bear in mind the reality of the laws that define our societies.
Which is why sound legal advice is crucial rather than relying on a web search and a simple cursory reading of the statute. Actual law is determined by statute; regulation, regulatory interpretation and practice relating to the statue; and judicial decisions and interpretation of the statute. For anyone in doubt or who is actually impacted by this issue, I would encourage you to consult (as I have done in the past) a Japanese attorney with expertise in this area.