1, Japanese bushido spirit
First of all, I want to mention the Bushido spirit, which is very popular in Japan. This spirit is both positive and evil. At that time, Japan invaded China, and this spirit really inspired the Japanese army and made their discipline more strict. But it also brought them some negative effects, that is, when they were ashamed of the emperor, they would commit suicide by caesarean section to show their loyalty to Japanese imperialism, and this spirit gradually spread to South Korea and North Korea.
2. Japanese cultural invasion.
After the Sino-Japanese War of 1894-1895, Korea was no longer a vassal state of the Qing Dynasty, but was occupied by Japan. After Japan took control of Korea, the Korean people rebelled because of its burning, killing and looting. The Japanese realize that it is not enough to control only in form, and it needs to be infiltrated in culture and spirit in order to keep this country for themselves forever.
Therefore, the Japanese carried out their own cultural invasion in North Korea, forcing North Korean children to know the wrong history and let them learn Japanese as their mother tongue from childhood, so that many North Koreans can't even tell whether they are Japanese or Korean. Therefore, when the Japanese instilled their language and culture into Korean children, they also gave them the spirit of Bushido, so suicide was not a very special thing at that time, and even let them watch others commit suicide.
3. Influence on Koreans
Such a deep-rooted culture has greatly changed their humanity and thoughts, so after Japan's defeat, they chose to commit suicide to work for the Japanese emperor, just because they always regarded themselves as Japanese, and Japan's bushido spirit and culture were stronger than the Japanese.