Ji Han Jae formed his new system of SungMuKwan Hapkido after extensive study of Yusool under Grandmaster Choi Yong Sool .
Ji Han Jae is another student of Grandmaster Choi Yong Sool .
Ji Han Jae , another student of Grandmaster Choi Yong Sool , formed his new system of SungMuKwan Hapkido after extensive study of Yusool under Grandmaster Choi Yong Sool .