Japan Post Bank signed a capital and business alliance with Matsui Securities on November 4, agreeing to buy 51,489,700 Matsui shares from the founding family's asset-management company in an off-market negotiated trade. The stake is 19.86% of issued shares but 19.99% of voting rights, and it makes the bank Matsui's largest shareholder once the transfer closes, planned for December 28, 2026.
The two percentages are not a rounding error. Matsui's voting-rights figure is calculated against total voting rights after excluding shares that carry none. Japan Post Bank itself describes the result as roughly 20% of Matsui's voting rights and says Matsui is expected to become an equity-method affiliate. (Earlier Tokyo Brief coverage is linked here for context: Earlier Tokyo Brief coverage.)
How the stake changes hands
Matsui says the founding family approached it in early 2026 about selling part of the holding of its asset company, about 20% of issued shares. Matsui and the family set the continuation of management policy built on its corporate culture and branding as key criteria for choosing a partner, and Japan Post Bank emerged as the leading candidate.
The seller's holding falls from 96,706,100 shares, or 37.55% of voting rights, to 45,216,400 shares, or 17.56%. That moves the family company from first to second place among shareholders. Matsui's notice gives no purchase price and lists no conditions to closing beyond the planned December 28 date.
Governance rights, and their limits
Matsui and Japan Post Bank agreed that the bank will respect Matsui's listing and independent management and impose no restrictions on its management other than those the agreement expressly sets out. The agreement does give the bank specific rights, most of them tied to its voting ratio.
| Term | What it says | Condition |
|---|---|---|
| Board nomination | Japan Post Bank may nominate one non-executive director; Matsui puts the nominee to the first shareholder meeting after nomination as a company proposal | Applies while the bank's voting ratio is 15% or more |
| Dilution consent | Matsui needs the bank's prior written consent to issue, dispose of or allot shares or take other dilutive action | Only while the voting ratio is 15% or more; certain exceptions |
| Bank's share sales | Bank needs Matsui's prior written consent to transfer shares | Exceptions include cases where the Banking Act or other law leaves no choice, and certain other grounds |
| Bank's extra purchases | Bank needs Matsui's prior written consent to acquire more shares | Certain exceptions |
| Top-up right | Bank may buy more shares, including in the market, to restore its voting ratio to 20% | If the ratio falls below 20%, for example after option exercises |
The consent right over dilution is the most consequential term. Matsui must obtain the bank's prior written consent before issuing, disposing of or allotting shares or taking other action that could dilute its voting ratio, subject to certain exceptions, and only while the ratio is at least 15%. The bank in turn needs Matsui's prior written consent to sell or buy more shares, with exceptions that include cases where the Banking Act or other law leaves it no choice on a sale.
Matsui's own assessment is that the effect on governance is limited. A minority holder with one board nomination, a dilution consent right and a top-up right is not a controlling shareholder under the terms described.
The commercial mechanism
The business alliance has four parts, and both companies say the details and methods will be settled separately.
- Referrals. The companies aim to send customers to each other. Matsui expects Japan Post Bank to refer active investors from its roughly 120 million accounts, including people moving from face-to-face brokers to online trading and high-asset customers, and to use its branch network and digital channels as touchpoints.
- Campaigns. The two will run joint campaigns.
- Products. Matsui will sell investment products created by Japan Post Asset Management, a Japan Post Bank subsidiary launched in April 2026.
- IPO introductions. Where the asset manager is general partner of a venture capital fund, it will introduce Matsui as one of the underwriting syndicate members to the fund's portfolio companies.
The bank's stated gap explains its interest. It says it does not currently handle stock or FX trading despite its customer base, and it sees a distribution channel for products the asset manager is considering, including ones using alternative assets. Japan Post Bank says the two companies plan to consider offering the asset manager's products through Matsui.
What it means for results
Both companies say the alliance's effect on results for the year ending March 2027 is minor at this point. Matsui adds that the shareholder change itself will not affect its results. The alliance is due to start on December 28, 2026, the same day as the planned share transfer.