NISA Investing vs Not Investing: Asset Gaps and Retirement Risk Seen in Japan's Household Survey, 2026 Edition

Summary

Japan's 2025 Family Income and Expenditure Survey shows that household finances are standing in a fairly delicate place.

For two-or-more-person households, monthly consumption expenditure averaged 314,001 yen per household. That was up 4.6% in nominal terms from the previous year, and up 0.9% in real terms after adjusting for price changes. It was the first real increase in three years.

But for worker households, actual income rose 2.8% in nominal terms while falling 0.9% in real terms. Disposable income also rose 1.9% nominally, but fell 1.7% in real terms.

In other words, income is rising if we look only at the surface numbers. But in real terms, closer to how households actually feel, conditions are still tight.

In this environment, the gap is not only about annual income.

The difference between a household that only protects itself with cash and a household that keeps emergency savings while also building financial assets through NISA or other long-term investment tools may become a source of asset gaps 10 or 20 years from now.

Of course, the household survey does not directly show an asset gap between NISA users and non-users. That point should not be confused.

Still, the 2025 household data is important primary information for thinking about cash, wages, spending, and financial assets in an inflationary environment.

What the Household Survey Shows About Japan in 2025

According to the Statistics Bureau of Japan's Family Income and Expenditure Survey, consumption expenditure among two-or-more-person households averaged 314,001 yen per month in 2025.

That was up 4.6% year on year in nominal terms and up 0.9% in real terms. Since real consumption expenditure had declined in both 2023 and 2024, 2025 marked the first real increase in three years.

At first glance, that makes household finances look as if they have recovered a little.

But the details are not quite that optimistic.

The Statistics Bureau explains that "food" continued to decline in real terms in 2025, while total spending was pushed up by a rebound in automobile-related expenses and higher spending on transportation and recreational services, partly related to Expo 2025 Osaka, Kansai.

So the burden of daily necessities has not simply disappeared. Rather, other spending categories lifted the overall total.

For households, the feeling is probably not "we are spending more because we have more room." It is closer to "some spending has increased because daily life, mobility, and services require it."

Why Wage Growth Still Does Not Feel Like Relief

The worker household data is even more uncomfortable.

Among two-or-more-person worker households, actual income averaged 653,901 yen per month. That was up 2.8% in nominal terms from the previous year.

Wages and income are indeed rising.

But after adjusting for price changes, actual income fell 0.9% in real terms. Disposable income was 532,408 yen, up 1.9% nominally but down 1.7% in real terms.

This gap is exactly the strange feeling many households have now.

Nominal income rises
        ↓
Prices also rise
        ↓
Disposable income after taxes and social insurance feels weaker in real terms
        ↓
Life does not feel easier

In this phase, it is a little dangerous to assume that higher annual income alone solves the problem.

Wage growth matters, of course. But when prices and social insurance burdens feel heavier than wage increases, households need to think not only about earning more, but also about how to protect and grow the money that remains.

New NISA Has Moved Into the Center of Household Strategy

The New NISA system began in 2024, and it has changed the way Japanese households think about asset formation.

According to Japan's Financial Services Agency, the 2024 NISA system made the tax-free holding period indefinite and made the system permanent. The annual investment limit is 1.2 million yen for the Tsumitate investment quota and 2.4 million yen for the Growth investment quota, or 3.6 million yen in total. The lifetime tax-free holding limit is up to 18 million yen, of which the Growth investment quota can account for up to 12 million yen.

For households, this is a major change.

The older NISA system required investors to pay attention to system deadlines and tax-free holding periods. Under the New NISA, the structure is easier to integrate into long-term household asset-building rules.

That said, New NISA is not a magic system.

NISA is a tax-free account wrapper for investment gains. It is not a product that guarantees gains. If that point is misunderstood, it can become an entrance to buying at high prices rather than a tool for asset formation.

The key point in this article is not that using NISA guarantees success.

It is a household strategy question: in an inflationary environment, how should a household allocate money between cash, emergency savings, and long-term investment?

What Changes Between Investing and Not Investing?

The difference between a household that invests and one that does not is not simply whether it owns stocks.

The core question is whether the household has an engine for asset growth inside its finances.

For a household that depends only on salary, the pace of asset formation is mostly determined by three things.

• Income
• Spending
• Savings rate

These are absolutely important. In fact, investing without emergency savings is the more dangerous choice.

But if a household builds assets only in cash, it is weak against inflation. The deposit balance may not fall, but the amount it can buy declines.

By contrast, a household that holds equities, investment trusts, or other financial assets over the long term takes price fluctuation risk, but may also capture corporate earnings growth, dividends, distributions, and compounding.

This is where the difference begins.

Even with the same annual income, a household that leaves every monthly surplus in deposits and a household that puts part of it into long-term investment may have very different asset structures 10 or 20 years later.

How Large Can the Difference Become After 30 Years?

Consider a case where someone invests 50,000 yen per month for 30 years.

The principal is 50,000 yen x 12 months x 30 years, or 18 million yen. That is exactly the same level as the New NISA lifetime tax-free holding limit.

If It Is Kept Only in Deposits

If interest is almost ignored, the asset value after 30 years is about 18 million yen.

That is not a bad thing. Deposits make it easier to preserve principal, and they are suitable for emergency savings and money needed in the near future.

However, if prices rise over those 30 years, the real purchasing power of that 18 million yen declines.

If It Can Be Invested at 3%, 5%, or 7% Annually

Assuming 50,000 yen is invested monthly for 30 years, excluding taxes and fees, and assuming annual returns of 3%, 5%, or 7%, the rough figures look like this.

A 7% annual return is a figure that assumes a fairly strong equity market can be captured over a long period. It does not mean assets rise by a stable 7% every year.

In real markets, crashes happen. The yen can strengthen or weaken. During the accumulation period, investors may also sit on large unrealized losses.

Even so, the long-term compounding difference is large.

This should not be read as "assets will definitely triple after 30 years." It should be read as "cash-only saving and long-term investing have different asset-formation structures."

What If We Compare a Household With 5 Million Yen in Annual Income?

Even after reading this far, some readers may still feel that investing is only for high-income households.

In reality, investing does not continue if the household has no room. Any article that pushes NISA while ignoring that point is dangerous.

So let us take a salaried household with annual income of 5 million yen as an example.

Assume that after living costs, housing costs, insurance premiums, communication costs, and other expenses, the household can allocate 30,000 yen per month to asset formation.

Investing 30,000 Yen Per Month for 30 Years

Excluding taxes and fees, and again assuming annual returns of 3%, 5%, or 7%, the rough figures look like this.

Future investment returns are not guaranteed, of course.

But the point of this table is not simply how much money can be made at 7%. The point is that even with the same income, a household that keeps all surplus cash in deposits and a household that puts part of it into long-term investment may move onto different asset-formation paths.

What matters is not only whether income is high.

It is how the household uses its surplus.

Even with 5 million yen in annual income, steady investing within a sustainable household budget can matter a great deal over time. Conversely, even a high-income household may struggle to build assets if it leaves no surplus and cannot continue investing.

Asset-Building Strategy Differs in Your 30s, 40s, and 50s

NISA is a useful system, but the same usage pattern is not right for everyone.

Investment horizon, household events, and risk capacity differ by age.

In Your 30s

The biggest advantage in your 30s is time.

Many people still have more than 30 years until retirement, making it easier to build a long-term accumulation plan centered on global equities, S&P 500 funds, or low-cost index funds.

Even if markets fall sharply along the way, there is time to wait for recovery. At the same time, this is also an age when childcare, home purchases, and job changes can shake household finances, so emergency savings should be separated first.

Time can work in your favor, but an investment amount that squeezes the household too hard will not continue. That quiet point matters.

In Your 40s

In your 40s, education costs, housing-related expenses, and retirement savings often overlap.

Income may rise, but spending can also expand.

At this stage, it is more realistic to separate money by purpose rather than lean too heavily into investment alone.

In your 40s, the issue is not only growing assets. It is also avoiding a mismatch between the timing of spending and the risk of the assets held.

In Your 50s

In your 50s, the balance between asset formation and asset defense begins to change.

With less time until retirement, there is no need to take risk in the same way as someone in their 30s.

The key risk is suffering a large market decline just before or just after retirement. If the money can wait for markets to recover, the problem is smaller. But if money needed soon for living expenses is placed in volatile assets, the household can come under pressure.

Starting to invest in your 50s is not too late.

But the purpose shifts from "grow aggressively" toward how to combine cash, bonds, investment trusts, pension income, and retirement benefits.

The right strategy changes with age.

Emergency Savings to Secure Before Starting NISA

The most important thing before investing is emergency savings.

Emergency savings means cash that allows the household to keep going when illness, unemployment, income decline, broken appliances, moving costs, or unexpected family expenses occur.

General Guidelines

The right amount depends on household structure and income stability.

If monthly living expenses are 250,000 yen, six months would be about 1.5 million yen, and twelve months would be about 3 million yen.

Why Emergency Savings Matter

Investment mistakes are not only about product selection.

In practice, being forced to sell because money is needed can be a major problem.

If living expenses run short while markets are falling, assets that were supposed to be held for the long term may have to be sold.

That can lead to realized losses, interrupted accumulation, and a broken asset-formation plan.

NISA should be funded with spare money. This principle is strong.

The New NISA annual investment quota is large, but using up the quota is not the goal. First secure emergency savings, separate money needed in the near future, and then gradually invest money that is unlikely to be needed for 10 years or more.

Asset formation is not a sprint.

It is far more important to stay in the market for a long time with an amount that can continue comfortably.

The Real Risk May Be Holding Only Cash

Many people think of investment risk as the risk of price declines.

That is correct. Stocks and investment trusts can fall normally. Losses can happen even inside NISA.

But when reading the 2025 household survey, another risk also comes into view.

The risk of holding only cash.

Even when wages rise in nominal terms, real income and real disposable income can fall. That also means price increases are eroding household purchasing power.

Cash has high short-term safety. But it is weak at protecting long-term purchasing power.

What is needed here is not a binary choice between cash and investment.

Living expenses
Emergency savings
Money needed in the near future
Money to grow over the long term

These four categories should be separated.

Money that will be used soon does not need to be placed in the stock market. In fact, it is usually better not to.

But if even money that is unlikely to be used for 20 or 30 years is kept entirely in cash, the household becomes quite exposed to inflation.

The "New Gap" Visible Through the Household Survey

The 2025 household survey is not a dataset comparing the future assets of NISA users and non-users.

Even so, there are things we can read from the statistics.

Households are under pressure in real terms even when nominal income rises. Real disposable income is also declining. Among worker households, the average propensity to consume was 65.0%, up 2.8 percentage points from the previous year. The surplus ratio was 35.0%.

In other words, how households use the money left over has become more important than before.

This is where the gap opens.

One household leaves surplus money in ordinary deposits without much thought.

Another secures emergency savings first, then allocates spare funds into long-term investment through NISA, iDeCo, taxable accounts, or other tools.

The difference may be hard to see in 10 years. Over 20 or 30 years, the difference in asset structure can become much larger.

This is a different kind of gap from an income gap.

Even with the same annual income, households that own assets and households that do not may differ in inflation resilience, retirement flexibility, and their ability to handle education or housing costs.

Asset gaps do not suddenly widen overnight.

They widen quietly through the accumulated effect of how each household treats its monthly surplus.

So What Should Households Do?

The first step is not to rush into filling the NISA quota.

There is an order.

1. Understand monthly fixed costs
2. Separate emergency savings
3. Keep money needed in the near future in cash
4. Start small with money unlikely to be used for 10 years or more
5. Keep the investment amount low enough that you will not be forced to sell during a market crash

The fifth point is especially important.

Long-term investing often fails not only because of product selection. It fails when the household becomes strained and is forced to sell during a downturn.

As the household survey shows, when real disposable income is weak, an overly ambitious monthly investment plan may not last.

NISA's tax-free quota is large, but using up the quota is not the goal.

The more realistic goal is to invest an amount that can continue without damaging household finances, and to stay in the market for a long time.

Conclusion: Future Asset Gaps Will Not Be Decided by Income Alone

What the 2025 household survey shows is fairly clear.

Nominal income is rising. But real income and real disposable income are weak. Consumption expenditure is increasing, and household breathing room can easily be squeezed.

In this environment, it is hard to discuss future household finances through annual income alone.

What matters from here is how households handle the money left after income and spending.

Cash is necessary. Emergency savings are necessary. Investing has risk.

Even so, in a society where inflation continues, being too heavily tilted toward cash quietly erodes purchasing power.

New NISA has become a powerful system for facing that risk. But NISA does not guarantee profits. It is a tax-free account for building assets over the long term.

Future asset gaps will not be decided by annual income alone.

Understanding household finances, keeping cash where it is needed, and growing spare funds over the long term. That plain, steady choice may matter a great deal 10 or 20 years from now.

Sources

• Statistics Bureau of Japan, Family Income and Expenditure Survey, 2025 Average Results, Income and Expenditure https://www.stat.go.jp/data/kakei/sokuhou/tsuki/
• Financial Services Agency, "NISA wo shiru" / Learn About NISA https://www.fsa.go.jp/policy/nisa2/know/index.html