It is an undisputed fact that the Korean writing system is the most creative and scientific one in the world.
It is also an undisputed fact that the Japanese writing system (hiragana & katakana) is only an abbreviation of Chinese. Koreans taught Japanese how to read and write since the 3rd century AD, but it was in the 15th century when the Korean writing system was invented.
It was already too late to educate the islanders.