Mizuho Financial Group and Sumitomo Mitsui Financial Group have joined a $1.75 million funding round for Japan's biggest bitcoin exchange, bitFlyer, according to Nikkei.
The groups made the investments through their venture arms, joining another Japanese giant, Mitsubishi UFJ Financial Group, as bitFlyer stakeholders.
The banks' interest in bitcoin and blockchain technology could be linked to their desire to bring down the costs of international wire transfers, suggests Nikkei.
Japan's banks have embraced fintech generally and blockchain specifically, but their hands are currently tied when it comes to acquiring promising startups in the sector by regulations that say their stakes in nonfinancial companies cannot exceed five per cent.
However, this rule could be changed within months, says Nikkei, improving the ability of banks to see off new upstart rivals and established tech giants such as Apple that are moving in on their territory.