 Whether the theory is probable or not, it is certain that "dangui" was worn during the Joseon period, based on historical documents and remains.The scholar, Yi Jae (李縡 1680 ∼ 1746) mentioned "dangui" in his book, "Sarye pyeollam" (literally "Easy Manual of the Four Rites") which defines four important rites based on Confucianism.In the chapter, "Gwallyejo" (冠禮條) on coming-of-age ceremonies, "samja" (衫子) is commonly called "dangui" and its length reaches to the knees and its sleeves are narrow.