Big Four Japanese firm Mori Hamada & Matsumoto and Simpson Thacher & Bartlett are advising the issuer of the largest initial public offering (IPO) in Japan this year. 

Yokohama-based Socionext Inc, a Japanese chip design firm formed from the system large-scale integration businesses of Fujitsu Semiconductor Ltd and Panasonic in 2015, is scheduled to make its $461 million IPO debut on the prime market of the Tokyo Stock Exchange on October 12.