The founders of two arts, Lee Joo-Bang () of modern Hwa Rang Do and Seo In-Hyuk (; Suh In-Hyuk) of Kuk Sool Won, are thought by some to have trained with Choi Yong-Sool, although this is controversial.
Students of importance who were trained by Choi during the later periods of his teaching were Kim Jeong-yoon, Kim Yoon-Sang () who later went on to form his own offshoot Hapki yusul organization to fabricate and support his erroneous and misguided claims of being the surviving grandmaster of hapkido [REF].