My Bank Paid Me ¥10,000 in Interest. Japan's Zero-Rate Era Is Officially Over

I opened my MUFG banking app and saw an unfamiliar number in the interest column.

Almost ¥10,000.

For context, Japanese savings accounts paid 0.001% interest for most of my adult life. That’s ¥100 per year on ¥10 million (roughly $65,000). Literally less than a single ATM fee. So seeing ¥10,000 — about $65 — felt like a glitch in the Matrix.

I told my wife. Her response: “Oh wow, nice.” She’s never once reacted to our ¥20 million in unrealized stock gains, but ¥10,000 in cold hard interest? That got a “wow.” Realized gains just hit different, I guess.

The math checks out: ¥9.5 million in regular savings × 0.30% annual rate = roughly ¥14,000 per half-year interest payment. But the fact that this math even produces a meaningful number — that’s what’s new.

300x Higher. Still Loses to ATM Fees

Japan’s megabank savings rate was 0.001% before March 2024. The Bank of Japan (Japan’s central bank, equivalent to the Fed) had maintained negative interest rates since 2016. As of February 2026, that rate is 0.30%.

Three hundred times higher. Sounds revolutionary until you do the math: ¥10 million in a megabank savings account earns about ¥30,000 per year before tax. That’s $195. Use an out-of-network ATM three times a month and your interest is gone.

Online banks tell a different story. Aozora Bank offers 0.75% on regular savings. Time deposits at SBJ Bank hit 1.35%. Government bonds (variable 10-year) are at 1.48%. Park ¥10 million in a time deposit and you’re looking at ¥120,000-130,000 per year. During the zero-rate era, the same deposit earned ¥100. At this point it’s basically a different financial product.

Honestly, I know I should move my ¥9.5 million from MUFG to an online bank. The rate difference is obvious. But inertia is powerful — my salary goes into MUFG, everything’s connected there, and the hassle of switching wins every time.

Variable Rate Mortgage: The Dream Is Over

The flip side of rising deposit rates? Mortgage payments.

We have a variable-rate mortgage — the overwhelming choice in Japan, where about 80% of borrowers go variable. Monthly payment was around ¥80,000 ($520). Somewhere in the back of my mind, I’d been dreaming that variable rates would just… never go up. That we’d ride the zero-rate wave forever.

Reality caught up last spring. Payments went up by a few thousand yen. Not devastating, but the signal was clear: the free ride is ending.

Here’s the timeline that matters. The BOJ has raised rates four times since ending negative rates:

• March 2024: -0.1% → 0.0-0.1% (ending negative rates after 8 years)
• July 2024: → 0.25%
• January 2025: → 0.50%
• December 2025: → 0.75% (highest in 30 years)

Variable mortgage rates don’t move immediately — there’s a roughly six-month lag. The spring 2025 increase I felt was from the July 2024 hike. The December 2025 hike will hit mortgage payments around July 2026.

And it’s not stopping. Market consensus expects rates above 1.0% by year-end 2026. At that level, a 1% increase on a ¥30 million mortgage means roughly ¥14,000 more per month — ¥170,000 per year. On ¥50 million, it’s ¥23,000/month.

Japan has a “5-year rule” that caps payment increases, so your monthly bill won’t spike overnight. But here’s the catch: the internal split between principal and interest shifts immediately. You’re paying more interest and less principal, even if the total looks the same. The debt shrinks slower. It’s a quietly unsettling mechanism.

Prepay the Mortgage or Keep Investing?

I’ve thought about it. More than once.

The rational answer: don’t prepay. Mortgage rate is around 1%. Expected return on index funds (our portfolio is All Country, FANG+, NASDAQ 100, and iDeCo) is 5-7% annually. The spread is massive. During the mortgage tax deduction period (up to 13 years in Japan, similar to the US mortgage interest deduction), the effective rate drops even further. iDeCo is the same story — when you factor in the retirement income deduction at withdrawal, maxing out tax-advantaged accounts beats prepaying the mortgage.

My brain knows this.

My gut wants to be debt-free. Looking at the mortgage balance and thinking “if only this were zero” — that feeling doesn’t respond to spreadsheets. Prepaying a mortgage or not is ultimately a personality question, not a math question.

My personal line: if rates hit 3%, I’ll seriously consider paying it all off. That’s purely emotional, not calculated. Just a “you know what, let’s be done with this” threshold.

But I also recognize that a mortgage is the cheapest loan a regular person will ever get. Borrowing tens of millions of yen at under 1% — no other loan product comes close. In the rent-vs-buy debate, if you frame the mortgage as leverage for investing the difference, buying has a real edge.

Interest Rates Suit the Japanese Temperament

Here’s something I keep thinking about: a world with meaningful interest rates is actually perfect for Japan.

Japanese people love cash. The majority don’t invest. Savings accounts are the default. It’s cultural — there’s deep comfort in money you can see and touch.

During the bubble era (late 1980s), time deposit rates hit 6%. Rule of 72: money doubled every 12 years. Basically, the entire nation was getting All Country-level returns just by parking cash in a bank.

The 30-year zero-rate period was, in a way, the worst possible environment for Japanese savers. Money didn’t grow, prices crept up, and investment felt alien. Telling these people to “just invest in index funds” was fighting against deep cultural wiring.

If bubble-era rates had persisted, I wonder what Japan’s personal wealth landscape would look like today.

My wife’s “wow” at ¥10,000 in interest captures something important. Unrealized gains are abstract — numbers on a screen that move. Interest is confirmed cash deposited into your account. For the majority of Japanese people who don’t invest, this “visible” benefit might be the most accessible upside of rising rates.

What I’m Changing (Almost Nothing)

The honest answer: nothing, for now. The ¥370,000/month investment plan continues as-is — I checked whether that level is actually sustainable, and so far the household budget holds up. Variable mortgage stays. MUFG account stays (too lazy to switch).

For a typical household, the impact isn’t dramatic enough yet to force changes. But I’ve noticed a subtle shift in mindset — a slight pull toward spending less frivolously. If rates hit 2%, I’ll probably think harder.

The government’s messaging is… confusing. They’re simultaneously pushing NISA (Japan’s tax-advantaged investment accounts, like a Roth IRA) to get people investing, while the BOJ raises rates in a way that makes savings accounts viable again. Pick a lane? Or maybe both lanes work. Investors benefit from rate normalization too, and savers finally get something back.

I wrote a companion piece on Note with the actual numbers: prepayment simulations, bank-by-bank interest comparisons, and the math behind the “invest vs. prepay” decision. If you want the spreadsheet version of this story, that’s where to look.

I’m part of a generation that only knew zero rates. This is our first time experiencing “normal.” And so far, it mostly looks like ¥10,000 showing up in a bank app — small enough to miss, big enough to notice.

※ This article reflects personal experience and is not financial advice. All investment decisions are your own responsibility.