The South Korean constitution guarantees freedom of speech, press, petition and assembly for its nationals. However, behaviors or speeches in favor of the North Korean regime, communism or Japan can be punished by the National Security Law, though in recent years prosecutions under this law have been rare.
There is a strict election law that takes effect a few months before elections which prohibits most speech that either supports or criticizes a particular candidate or party. One can be prosecuted for political parodies and even for wearing a particular color (usually the color of a party).[43]
The UN Human Rights Commission expressed concerns about South Korea's deterioration of online free speech.
https://en.wikipedia.org/wiki/Freedom_of_speech_by_country#South_Korea


