Tokyo’s blueprint for transition finance: How Japan is leading regional decarbonization

Since the Japanese government issued the world's first sovereign transition bond in February 2024, it has raised roughly USD 25 billion under the GX Economy Transition Bond program — accounting for some 62 percent of global transition bond issuance and dwarfing every other sovereign player in the market. Underpinning that issuance is the GX 2040 Vision, an ambitious plan to mobilize USD 1 trillion of public and private capital for Japan's green transformation in the coming decade.

“Transition bonds are one of the very important platforms in Tokyo, and we have established multiple successful track records,” says Tokio Morita, executive director of FinCity.Tokyo, the body charged with promoting the Japanese capital as a global financial center.

Morita emphasizes that these successes are built on a framework that differentiates Japan from its peers: sector-specific decarbonization roadmaps for hard-to-abate industries, developed with the public sector at the table rather than as standalone corporate exercises.

“It is not a voluntary roadmap...That should address concerns that transition finance is undermining climate change initiatives,” explains Morita. “That kind of structure is very established in Tokyo.”

The credibility argument is important because transition finance still has an image problem in some international markets, where critics worry it will prolong the life of high-emission industries. But the tide may be shifting in Japan's favor. The Climate Transition Bond Guidelines published by the International Capital Market Association (ICMA) in November 2025 align closely with the approach Tokyo has been refining for years.

“The Japanese framework should be elevated to an internationally accepted one,” suggests Morita. “We are trying to make our approach internationally interoperable, and in that context the ICMA guidelines on transition bonds will be a great help.”

One aspect of that internationalization is an ongoing partnership with London, including a joint Transition Finance Forum with the City of London's Transition Finance Council, alongside a working-level UK–Japan Transition Planning Dialogue bringing together stakeholders from the two national governments, the two cities’ bourses, academics and industry representatives. Memoranda of understanding have also been signed with Frankfurt and Luxembourg.

Another crucial element is building on Tokyo’s broader regional role: one connecting global capital with credible decarbonization pathways across Asia, from heavy industry in Japan to power generation in Southeast Asia.

“Climate change is a global agenda, and many Asian emerging economies are higher-emission countries. A brown/green binary taxonomy wouldn't work. The transition finance concept is very, very important to them,” Morita observes.

Sell-side practitioners structuring transition finance instruments echo that diagnosis. Kotaro Sueyoshi, head of the Sustainability Promotion Department at Mizuho Securities, puts the issue in stark terms: “The key question today is not whether to decarbonize, but how to do it in a way that is economically sustainable. For us, transition is not a compromise. It is a pathway to achieving both sustainability and economic growth at the same time.”

For an economy with Japan's manufacturing base, demographic pressures and structural dependence on imported energy, that framing is not optional, he argues.

Mizuho has structured transition deals across electricity and gas, iron and steel, shipping, heavy industries and chemicals, and Sueyoshi sees the ICMA guidelines as a turning point. He believes the Climate Transition Finance Handbook sets out what credibility requires: clear targets, strategy, timelines and achievability, while the bond guidelines translate those credentials into financing terms.

“Now we have both sides aligned…we will start to see more concrete and scalable transition finance going forward,” he adds.

According to Sueyoshi, the next stage of growth hinges on clearer disclosure — particularly around ‘avoided emissions,’ the climate benefits a company’s products or services enable elsewhere in the economy. Mizuho published its Avoided Emissions Focus Report last year and has taken Japanese heavy-industry clients into the COP discussions to make the case.

“Avoided emissions are critical because they capture the real contribution a company makes to decarbonizing society, not just reducing its own carbon footprint,” says Sueyoshi.

The distinction matters most for the new technologies that transition bonds are increasingly being asked to fund, such as hydrogen, energy efficiency and low-carbon industrial solutions.

Sueyoshi suggests the character of the market is also shifting: “The market is reaching a mature phase, and sustainable bonds today are about creating a platform for strategic dialogue between issuers and investors.”

He sees that perspective as gradually replacing the focus on a ‘greenium’ — a reduction in borrowing costs compared to conventional bonds. He says that institutional investors “are more committed to sustainability than ever before. They really want to generate impact through their investment.”

Where global investors fit into that picture is a central question for Reiko Hayashi, former director and deputy president of BofA Securities Japan. A capital markets veteran of more than three decades who worked on underwriting some of Japan's first green bonds in 2014, Hayashi casts a genuinely international eye on developments.

“When I started underwriting green bonds, Japanese market participants didn't even know what they were. Awareness now is incomparably stronger,” says Hayashi, who has also sat on multiple government working groups and is now a senior advisor to the ICMA.

“Transition finance is one of the areas where Japan can lead the global market,” she suggests. “Asian countries cannot implement what Europe is doing in the same manner, so the Japanese approach is a good model to follow. It is very inclusive.”

That model is already being picked up. Korea has built its own transition finance framework explicitly tracking the Japanese template — branded ‘K-GX’ in a nod to the country’s cultural exports — and the UK government has examined Japan's guidelines closely. The Tokyo-London Financial Seminar 2026 in London earlier this year brought UK and Japanese officials together with major investors discuss exactly how those approaches can be aligned in practice.

Hayashi also points to a quieter but increasingly significant new frontier: resilience finance. BofA Securities acted as lead manager on the Tokyo Metropolitan Government's Transition Resilience Bond issued last autumn. These are the first such issuance from a Japanese regional government, are certified by CBRT and aligned with the ICMA Social Bond Principles as well as FSA Social Bond Guidelines.

“It was highly accepted by international investors, especially in the European market. Resilience is a really strong theme for everybody as it is related to daily life,” says Hayashi.

With the Climate Bonds Initiative now formally connecting climate resilience to transition, and physical climate risk climbing up the global agenda, the category looks set for growth. Mizuho’s Sueyoshi adds that Tokyo's own real economy is a natural laboratory for that expansion.

“Tokyo has very significant potential as a global transition finance hub. It is Japan's largest energy demand center, and the Tokyo Metropolitan Government has already demonstrated leadership through resilience bonds, bringing the scope of sustainable finance beyond mitigation to include climate adaptation,” says Sueyoshi. “If Tokyo can scale these initiatives, it can play a leading role not only for Japan but as a model for cities across Asia.”

Despite macro headwinds in the form of super-long JGB yields spiking sharply in May and a more cautious investor mood keeping some international participants on the sidelines, the structural argument remains solid. April 2026 saw Japan's GX Emissions Trading System (GX-ETS) become fully operational, with the promise of eventually giving issuers and investors the kind of robust emissions data that has been a weak point in the Japanese disclosure ecosystem. Sueyoshi expects the new system to act as a “catalyst” for improved KPI transparency among issuers, particularly in high-emitting sectors, as well as drive demand in Japan’s compliance credit carbon market.

Meanwhile, Hayashi argues that it is “too early to tell” what the impact of the new system will be but urges policymakers to keep the framework inclusive: “If we make it too strict, people will lose the momentum to get involved, especially issuers.”

Morita believes Tokyo can leverage its unique position to carve out a distinctive regional role: “We are the only G7 country in Asia. We have the connection to the highly sophisticated concept and standards, and at the same time we know the reality in Asian countries. So, we can be a bridge between them.”