This is a Japan-specific tax scheme. If you are not a Japanese tax resident, it does not apply to you, or different rules will apply where you live.
How it works
The Tsumitate Investment Quota is one part of the new NISA's tax-free allowance, and the eligible products are limited to certain mutual funds considered suited to long-term, installment-based, diversified investing.
Difference from the Growth Investment Quota
The new NISA also includes a Growth Investment Quota (see related page), and the two can be used together. The Growth Investment Quota covers a broader range of products, including individual stocks, which is the main difference from the Tsumitate Investment Quota.