BASE's largest shareholder raised his holding in the e-commerce platform operator to 26.89% from 24.52%, according to a large-shareholding change report (No. 11) filed on 19 October 2026. The 31,718,186 shares he holds are measured against 117,937,657 shares outstanding as of 9 October, the date the reporting obligation arose. The report was triggered by a rise of one percentage point or more. Earlier Tokyo Brief coverage
Four market purchases in October
The report lists four on-market purchases of common stock: 3,288,000 shares on 2 October, 1,412,000 on 5 October, 627,000 on 7 October and 2,175,000 on 9 October. It gives no unit prices.
The report's acquisition-funds section puts total funding for the holding at ¥12.95bn. His own funds account for ¥3.11bn, and ¥9.84bn comes from margin trading with Tachibana Securities. The borrowings section is blank. The report does not tie the funding to the four October purchases individually. He also holds a margin buy position of 24,084,700 BASE shares with Tachibana Securities.
What he says he will do
The shareholder says a year of friendly engagement ended without the result he wanted. The confidentiality agreement he signed with BASE on 29 August 2025 was extended twice and ended on 28 August 2026. He now says he has doubts about the effectiveness of internal controls meant to keep directors' conduct lawful and proper, citing how shareholder-related decisions are made, how information is handled and checked for accuracy, and how problems are found and fixed. These are his own assertions, and the report does not present them as established findings.
He is dropping his earlier policy of not exercising voting rights. He says he will assess each director's judgment, explanations and oversight record, and may vote against the election of individual directors.
Once the tender offer for BASE common stock launched by SBINM on 31 August 2026 ends, he plans to put a proposal to BASE on a change in board structure, specifically a move to a company with nominating and other committees. The report says this may not take the form of a formal shareholder proposal.
Above 30%, with conditions
He says he aims to acquire more than 30% of voting rights, to make his voting and engagement more effective. If he actually reaches 30% or more on a voting-rights basis, he says he will do so in compliance with the takeover-bid rules of the Financial Instruments and Exchange Act and other laws. The report does not say how or when. His 26.89% is a share-count ratio, so the voting-basis target is a separate measure.
He still backs the capital and business alliance that SBI Holdings and BASE signed on 28 August 2026, calling it beneficial to BASE's corporate value. He says that support is compatible with voting to press for better board oversight.
He also says he will review any takeover defence or third-party share allotment individually, and will seek a provisional injunction or other legal action if he judges there are grounds to block it or otherwise considers it necessary. The report does not say BASE has proposed either.