The all-stock deal bolsters SBI's crypto exchange services in Japan.
A potential partnership between Binance and TaoTao fell through, 10 months after first being revealed.
The exchange said it is discussing a strategic partnership with a Softbank subsidiary and Japan-based exchange TaoTao to work together to provide "trading services" in the country.
A new crypto exchange platform in which Yahoo Japan owns a major stake is about to launch after over a year in development.