Nikkei Shinbun writes up an article telling people "Well, it's so good for you, it's for your (and bureaucrats') convenience in mind."
"Mai Nanbaa", or My Number if it were in English, but the word is actually what I would call "Japlish" - a strange class of words that uses English words but the original meaning of English word is totally lost on the Japanese. It's much like "Mai Kaa" or My Car, which is in Japan a car that you own for your private use.
"Mai Nanbaa" will be like "Mai Kaa", your own cute little number that goes with you wherever you go.
The same concept had been tried by politicians for decades, but each time it met a resistance. The concept had a different word assigned to it - 国民総番号制度, which literally says "Assigning every single citizen with ID number".
So, the politicians and those who are closely connected to the politicians got smart. First, they diluted and loosened the Japanese language with strange-sounding Katakana English (which I call "Japlish") so that no one can actually figure out exactly what these strange words mean. Then, they introduce this "Mai Nanbaa", without quite telling the citizens that it is a tired old effort given a new facade. Oh it's just like "Mai Kaa", it means it's just so you.
The Kan administration tried to push the "Mai Nanbaa" bill in June 2011, but Mr. Kan stepped down as the prime minister and the bill went nowhere.
The whole point of assigning every single citizen with ID number is to collect taxes more efficiently and ruthlessly, to detect the fraud (very rare in Japan), and most importantly, to save time for the bureaucrats as Nikkei gushes.
There doesn't seem to be any way to opt out.
From Nikkei Shinbun (3/1/2013; part):
「マイナンバー」16年から 税や年金手続き簡単に 政府が法案提出
"My Number" to be introduced in 2016, tax filing and pension application will be easier. The government has submitted the bill.
The national government will introduce "national identification number system" in 2016, which will assign one personal number to each citizen to manage social security payments like pension and health insurance and tax filing. The system will make social security application and tax filing easier, and will lead to accurate collection and distribution of taxes and social insurance premiums. Building of the government IT infrastructure for efficient administration and finance is set to start.
On March 1, the Abe administration approved the bill by cabinet decision, and submitted the bill to the National Diet. The original bill was abandoned because of the dissolution of the Lower House last year, but it has since been amended by Liberal Democratic Party, Komei Party and Democratic Party of Japan. It is highly likely that the bill will pass in the current ordinary session of the Diet, but it is possible that the passage is delayed depending on the situation toward the end of the session.
To efficiently install systems in ministries and agencies that will use the number system, a bill has also been submitted to create a position of inspector general of Cabinet Telecommunication Policy (Government Chief Information Officer) within the Cabinet Secretariat.
The advantage of the number system is that it will save a lot of trouble in complex administrative procedures.
By bundling multiple procedures of an individual into a single number, it will be possible to collect and distribute the proper amount of taxes and insurance premiums. The government [administration] believes it will be easier to prevent double application of tax exemption for dependents when two children each claim the exemption for the same mother.
Consideration will be given to privacy, and management of the numbers will be strict.
Two children claiming tax exemption for their mother? Big deal. Don't they have a better target to go after? Oh I forgot - a better target is an easy target.
Strict management to protect privacy. Sure.
The previous DPJ administration under Naoto Kan didn't even know they had the emergency teleconferencing system when the real big emergency hit them on March 11, 2011. The system remained unconnected. There is no reason for me to believe the LDP administration under the pork cutlet prime minister to be any different.