April 2025 Was a Switch, Not a Finish Line: the English Disclosure Mandate

TL;DR - From 1 April 2025, all ~1,640 domestic Prime-listed issuers must release financial results (kessan-tanshin) and timely-disclosure (tekiji-kaiji) material in Japanese and English at the same time — a hard listing-rule change, not a recommendation. - The TSE FAQ permits excerpt or summary translations instead of full bilingual versions, and carves out cases where simultaneity would delay urgent Japanese disclosure (M&A, cyber incidents, leak prevention). - The YUHO (annual securities report), convocation notice and corporate governance report are out of scope for now, but the FSA's June 2025 Action Programme has already flagged each of them for 2026-27 extension. April 2025 closed the easy half of the file.

A rule, not a request

The English-disclosure conversation in Japan is unusual in one respect: for ten years it was almost entirely a soft-law exercise. Foreign investors complained, the TSE issued surveys, the Code carried Supplementary Principle 3-1 ② asking Prime issuers to disclose "information disclosed under laws and regulations in English to the extent reasonable." Companies did what they wanted. By late 2024, almost every Prime issuer was producing something in English, but only about 30% were doing so simultaneously with the Japanese release. For a foreign analyst on US East Coast time, a six-hour delay was the difference between a tradeable insight and a one-day-old news clip.

The switch flipped on 1 April 2025. The Tokyo Stock Exchange's listing rule amendments — adopted in January 2024 and previewed in the TSE Council of Experts' "Policy on the Expansion of English Disclosure in the Prime Market" published 27 March 2023 — made simultaneous Japanese/English disclosure of two specific document classes mandatory for every domestic Prime issuer:

1. Financial results (決算短信, kessan-tanshin) — both quarterly and annual.
2. Timely-disclosure information (適時開示, tekiji-kaiji) — the catch-all category routed through TDnet for material events: M&A, dividend changes, capital actions, earnings revisions, material legal/operational events.

Two design choices in the rule deserve attention.

First, simultaneity is the substantive obligation. Companies are not asked to translate everything. They are asked, on a per-document basis, to publish in English at the same moment the Japanese version is published. A Prime issuer that has already been translating its kessan-tanshin into English on a T+3 schedule has been "complying" with the prior soft-law expectation but is in clear breach of the April 2025 rule.

Second, the TSE FAQ permits "excerpt or summary translations". A full bilingual document is not required; a faithful summary of the key contents is acceptable. This is the rule's pragmatic concession — most kessan-tanshin run to 30+ pages of Japanese-language detail, and the TSE recognised that requiring a full translation in five hours after a Friday-evening earnings release would be a quality-destroying mandate. What you owe is the substance, in English, at the same time.

What "simultaneous" actually means

The TSE's December 2024 implementation survey gave a precise baseline. Among Prime issuers (then 1,654, now 1,634 after delistings):

The headline number — 99.0% disclose something — was meaningless. The TSE's published intent was always to lift the simultaneity rate from the 30% range to "near universal." By the FY2025 monitoring round, the published figure jumped to over 90% simultaneous compliance, a near-overnight shift that confirms what regulators had suspected: the gating constraint was not capacity, it was effort.

A subsidiary effect is now visible in the data. Companies that had outsourced English disclosure to a third party on a delayed-translation contract have been forced to bring at least the summary work inside their IR function or to renegotiate for real-time turnaround. Vendor pricing for bilingual disclosure rose roughly 25-40% between Q1 2024 and Q1 2025, then stabilised once the rule took effect and most issuers had built durable workflows.

The coverage rollout, in one table

Below is the practical view IR teams should hang on the wall.

The structural pattern is the same one Japan has used for every disclosure mandate since the 2022 market restructuring: start with the highest-frequency, lowest-detail documents; build to the lower-frequency, higher-detail ones; let the largest issuers go first. The YUHO is the obvious next domino because the FSA's June 2025 Action Programme for Corporate Governance Reform explicitly named it, and because the SSBJ phase-1 issuers will need a bilingual statutory-report channel from FY March 2027 anyway. The convocation notice is harder politically — it is regulated by the Companies Act, not the FIEA, and the Ministry of Justice will need to bless any reform — but the working-group discussion is now active.

The four carve-outs in the FAQ

The TSE's English Disclosure FAQ is the practical document IR teams should bookmark. Four exceptions to strict simultaneity matter:

1. The speed carve-out (M&A, capital actions, sudden management change). Where preparing an English version would delay the Japanese disclosure beyond the regulatory timetable, the Japanese release has priority and the English version may follow "as promptly as possible." The FAQ frames this in terms of preserving the market-integrity purpose of timely disclosure: a 30-minute delay to draft English is acceptable; a four-hour delay to do a polished bilingual press release is not.

2. The cyber-incident carve-out. A cyber incident must be disclosed under the operational-impact branch of TSE's timely-disclosure rules as soon as the issuer judges it material. The FAQ explicitly contemplates that English drafting may take longer than the obligation to inform the Japanese market — and confirms that this is acceptable. The carve-out is a recognition that incident-response and disclosure-drafting compete for the same internal bandwidth in the first 24 hours.

3. The leak-prevention carve-out. Some material disclosures require coordinated release across multiple venues to prevent selective leak — for example, a TOB announcement that needs to land at the same minute as a stock-exchange filing in another country. Where the bilingual production cycle would create a leak window, Japanese release can precede English, with English following "without undue delay."

4. The legal-precision carve-out. Where the Japanese filing contains contractual or regulatory language that cannot be safely translated under time pressure — for example, the precise wording of a court order or a settlement agreement — the FAQ accepts a clearly-labelled English summary, with the warning that the Japanese text is controlling. This is the closest the TSE comes to acknowledging that English disclosure in Japan is, legally, a courtesy to the global capital market, not a parallel-authoritative filing.

The four carve-outs together describe the rule's centre of gravity: simultaneity is the default; exceptions are narrow, named, and have to be justifiable on the speed-of-Japanese-disclosure principle.

What the September 2025 overseas-investor survey said

The TSE's September 2025 Survey of Overseas Investors on English Disclosure is the post-implementation report card. Three findings are now load-bearing for the next phase of policy:

• Translation quality is the new complaint. With simultaneity essentially solved, overseas investors' single largest dissatisfaction migrated to translation quality — specifically, machine-translation boilerplate that obscures rather than conveys the underlying Japanese sentence. The survey cited several Prime issuers by name for inverted clauses, mistranslated KPIs and untranslated table headers.
• The YUHO is the most-cited gap. 67% of surveyed overseas investors said they would value full English YUHO disclosure within one quarter of the Japanese filing. This is the FSA's political mandate to extend the rule.
• Convocation notices remain a structural problem. Overseas investors complained that voting periods are compressed by the late arrival of English convocation notices — sometimes only one week before the meeting, against an ISS deadline that requires earlier visibility. The June 2027 AGM season is the implicit deadline for a fix.

The survey's quiet finding is that the rule's enforcement model is monitoring + naming, not penalties. The TSE has not used the listing-rule's penalty schedule against any issuer for non-simultaneous disclosure in the first year. Instead, the monthly TDnet release and the TSE's published implementation reports name laggards by issuer code. As with the cost-of-capital disclosure-list mechanism that TSE deployed in 2024, publication is the discipline.

Why the rule was deeper than it looked

Three structural reasons explain why a rule that looks like a translation-services mandate is in fact one of the more important Theme-5 items.

First, the rule rewires the IR function's relationship with corporate communications. Before April 2025, English disclosure was an output of a corporate-communications team working with translation vendors on a T+1 schedule. After April 2025, English disclosure is a pre-publication workflow that has to be inside the same revision pipeline as the Japanese draft. That has knock-on effects on internal review cycles, legal sign-off and disclosure-control documentation. Several Prime issuers we surveyed have moved their English-disclosure desk inside the IR function, not the PR function, on the grounds that simultaneity demands ownership by the team that signs off the substance.

Second, the rule is the gateway to the SSBJ filing channel. SSBJ-aligned sustainability disclosures for Phase-1 issuers go into the YUHO from March 2027. The YUHO is the FSA's statutory disclosure document, and the FSA's clearly-signalled intention is that Phase-1 issuers will file SSBJ-aligned text in both Japanese and English. The bilingual pipeline that Prime issuers built for tekiji-kaiji in 2024-25 is the same pipeline that will carry SSBJ disclosures in 2026-27. Issuers that under-invested in the April 2025 rule are now visibly behind on SSBJ readiness — a point we return to in Post 5.5.

Third, the rule changes who reads the Japanese document. Once an English version exists in parallel, the marginal foreign investor reads the English text and references the Japanese only for legal precision. A subtle effect is that the Japanese text starts being written for the English version: management commentary becomes more linear, more thesis-led and less rhetorical, because the translator has to render it. This is, in our view, the deepest of the structural effects, and is visible in the FY2025 management commentaries of issuers that took the rule most seriously.

A field note on translation quality

The most actionable IR question after April 2025 is: how good does the English have to be? Three quality bars are now visible in the market.

Bar 1 — Faithful summary. Captures the major topic, key numbers and a one-paragraph management view. Acceptable under the FAQ; the floor of compliance. Roughly 40% of Prime issuers operate at this level for tekiji-kaiji.

Bar 2 — Substantive parity. Renders all material content in idiomatic English, preserves tables and numerical detail, and gives a foreign reader equivalent decision-useful information. The expected standard for kessan-tanshin among large-cap Prime issuers.

Bar 3 — Investor-grade. Idiomatic, narrative, and edited by a bilingual IR or finance professional. Carries the editorial voice of the issuer's English IR persona. Currently practised by a sub-population of <50 Prime issuers, but the standard the September 2025 overseas-investor survey is implicitly demanding.

The IR teams that have moved fastest in 2025-26 are those treating Bar 2 as the floor and budgeting for Bar 3 on the documents that drive engagement (earnings, mid-term plan announcements, governance-related disclosures). The IR teams that are exposed are those whose translation contracts still produce machine-translation drafts with light editing, on the assumption that volume not quality is the test. The TSE has been clear that this assumption is wrong.

Sidebar: the GATE and the toolbox

The JPX runs the English Disclosure GATE, a portal that consolidates English-language disclosures by issuer and document type. It is the practical entry point for foreign investors who want to track a Japanese issuer's English-language information flow. IR teams should:

1. Verify that every English release the company files reaches the GATE — this is automatic for TDnet-routed disclosures, but optional materials posted only to the company website do not appear.
2. Track the issuer's GATE-listed simultaneous-disclosure rate; this is one of the metrics the TSE uses in its survey work.
3. Use the GATE's search functionality to benchmark against peer issuers — particularly useful for IR teams that want to assess whether their own English release cadence matches the segment leader.

What this means for IR

1. Build a single bilingual disclosure pipeline, not parallel ones. Treat the English version as a non-negotiable output of the Japanese drafting cycle, not as a downstream translation step. The legal review, the disclosure-control checklist and the management sign-off should all touch both versions before either is released.
2. Target Bar 2 quality on every document, Bar 3 on the four or five that drive engagement. The four-or-five usually are: full-year earnings, mid-term plan announcement, any cost-of-capital / PBR action plan disclosure, any board-composition / governance report update, and any material M&A press release.
3. Audit your performance against the carve-outs. If you used the speed carve-out more than twice in FY2025, you have a process problem, not a rule problem. The carve-out is a safety valve, not a routine practice.
4. Get ready for the YUHO extension now. The FSA has signalled — through the June 2025 Action Programme and the SSBJ phase-in schedule — that bilingual YUHO is coming for the largest issuers from FY2026 filings. If you are a Phase-1 SSBJ issuer (market cap above JPY 3 trn), you should already be designing the bilingual production cycle for next March's YUHO.
5. Stop reporting "we disclose in English" as a comply line. The 99.0% figure has made the binary metric meaningless. What overseas investors read in your CG report is what you disclose, when, and at what quality. State your simultaneity rate, the document classes covered, and the quality tier you target.

Sources & further reading

• TSE Council of Experts, "Policy on the Expansion of English Disclosure in the Prime Market" (27 March 2023): https://www.jpx.co.jp/english/equities/follow-up/b5b4pj000004yqcc-att/u5j7e50000000l3i.pdf
• TSE, "Status of Mandatory English Disclosure in the Prime Market" (September 2025): https://www.jpx.co.jp/english/equities/follow-up/b5b4pj000004yqcc-att/sjcobq0000024jy9.pdf
• TSE press release, "Results of the English Disclosure Implementation Status Survey as of the End of December 2024" (22 January 2025): https://www.jpx.co.jp/english/corporate/news/news-releases/0060/20250122-01.html
• TSE, "Results of the 2025 Survey of Overseas Investors on English Disclosure by Japanese Companies" (September 2025): https://www.jpx.co.jp/english/corporate/news/news-releases/0060/20250902-01.html
• JPX English Disclosure GATE: https://www.jpx.co.jp/english/equities/listed-co/disclosure-gate/service/index.html
• FSA, "Action Programme for Corporate Governance Reform 2025" (30 June 2025): https://www.fsa.go.jp/en/news/2025/20250630-1.html

Next in this theme: 5.2 The End-Game of Cross-Shareholdings: from comply-or-explain to per-stock verification

Related posts in other themes: - 2.3 The 2021 Revision: Prime, sustainability, diversity - 3.1 From Four Segments to Three: the April 2022 restructuring - 4.3 The Shame-and-Showcase List: how TSE polices participation through publication - 5.5 SSBJ in Action: the three-phase sustainability disclosure roll-out