Wikipedia
Sōshi-kaimei
Sōshi-kaimei (創氏改名) was a policy of pressuring Koreans under Japanese rule to adopt Japanese names. It consisted of two parts. Ordinance No. 19, issued in 1939, required sōshi, literally "creation of a ; unlike Japan, Korea had not adopted the Western practice of universally using family names (see ). Ordinance No. 20, issued in 1940, permitted kaimei, change of one's given name; this was voluntary and the applicant was charged a fee.
These ordinances, issued by General Jirō Minami, Governor-General of Korea, effectively reversed an earlier government order which forbade Koreans to take up Japanese names. There are various explanations for the purpose of the ordinances.