NISA accounts were created by the government to encourage people to invest their savings. They offer tax-free investing for a period of five or twenty years (depending on the type of NISA account that you choose).
You can invest up to the yearly allowance (400,000 or 1.2 million for adults, or 800,000 for children) and can access your money at any time.
This is a comprehensive guide to Japan's NISA accounts in PDF format. What they are, what they are for, who should open one and who shouldn't, how to choose a provider, what investments to make and how to manage the account.
Includes a step-by-step guide to help anyone successfully open and set up their account.
Anyone who buys a RetireJapan Guide will automatically have access to free copies of subsequent updates and editions.
RetireJapan is the best (and only?) English-language personal finance website for residents of Japan and this is one of a range of personal finance guides.
*If you are comfortable reading in Japanese, I recommend you pick up Minako Takekawa's book on NISA instead.
**It appears NISA accounts are not a good fit for US citizens and green card holders (basically anyone who has to file a tax return with the IRS). Please see the RetireJapan site for more details.