South Korea's Mirae Asset Securities plans to buy Sanko Securities, a Tokyo trading firm owned by Okasan Securities Group, for about 47.6 billion won (about $35.5 million). Its board approved the deal today (Thursday), the company said in a regulatory filing.The purchase gives Mirae a registered Japanese securities firm in a market where retail broker traffic is rising.Organic visits from Japan to the websites of retail FX and CFD brokers tracked by FM Intelligence rose 18.5% quarter-over-quarter to 6.6 million in Q3 2026, its heat map shows. Traffic from the Asia-Pacific region as a whole fell 33% over the same period.London's trading industry is coming home!The buyer will be Mirae's US subsidiary, Mirae Asset Securities Holdings (USA) Inc., which is set to receive 12 billion yen (about $76 million) from its parent. Part of that pays for the shares, and the rest goes into Sanko after closing, according to the filing.The price will be fixed at closing, which needs regulatory approvals. Sanko's own board has yet to approve the sale, and the filing said the deal could change depending on that vote.How Foreign Brokers Have Entered JapanJapan's retail market already has more than 150 providers and over 3 million active FX trading accounts. The foreign firms that targeted it recently did so through local units of their own.Interactive Brokers' Japanese arm added tax-free NISA accounts in mid-2025, and Capital.com started hiring a compliance head to apply for a Japanese license in August that year.Deals have been less frequent. In 2020 Gaitame, owned by Swiss-listed Compagnie Financière Tradition, took over the FX clients of Livestar Securities, and SBI Holdings bought the rest of Livestar in the first M&A in Japan's online brokerage sector in many years.Mirae's purchase of Sanko follows that second route, buying an existing registered firm instead of applying for a new one.From Proprietary Trading to RetailSanko trades stocks, bonds and other securities with its own capital. It reported net assets of 39.1 billion won and net profit of about 400 million won for the year to March 2026, the Korea Times reported.Mirae plans to build on those trading operations, widen sales of financial products and eventually run a full retail brokerage in Japan, according to the newspaper.A company official described the purchase as "an important step toward establishing a foothold in Japan."Mirae first said it was studying a Japanese acquisition on August 27, after the Korea Economic Daily reported that it and Toss Securities were preparing to buy brokers in Japan.Mirae called the matter undecided again on September 23. Its predecessor, Mirae Asset Daewoo, withdrew from Japan in 2016.The 12 billion yen injection equals about 0.75% of Mirae's 13.48 trillion won in equity at the end of 2025, below the 2.5% threshold that triggers a mandatory disclosure, the company said.The Sanko price is about a tenth of the 480 billion won Mirae agreed to pay for Indian broker Sharekhan in December 2023.A retail business would compete with incumbents such as Rakuten Securities, whose account base crossed 14 million in April.It would also face Japan's push for stronger login security. After account hijackings worth over 500 billion yen between March and May 2025, 76 brokerages committed to making multifactor authentication mandatory.This article was written by Damian Chmiel at www.financemagnates.com.