The Hallyu (Korean Wave) boom that started with TV dramas in the 2000s expanded to various cultural areas, including food and music. As Korean culture gained popularity, Hallyu fans in Japan began to adopt Korean vocabulary like loan words. To study this phenomenon, the author collected vocabulary used by K-pop fans of native Japanese speakers and classified them by type. It was found that most of these words were currently being borrowed and used in their original Korean form; however, there were also words created by combining Korean words with Japanese words or newly coined by combining Korean words. Once Korean K-pop vocabulary becomes more established in Japan, it is expected that more words will emerge that originate from Korean but are independently created and used exclusively by Japanese speakers.