Whear i come from the only thing you can study is korean martial arts. there is TKD, KSW and hapkido. But almost all the instructors from each club originated from the same hapkido master. So when I go to turniments there are many similarities between the styls. I take Hapkido and have done some reserch. As was said the information can be taken differently but this is what I have descoverd. The founder of hapkido is master choi, im not sure exacly how but he ended up in japan whear he was taught by his master (dont recal his name at the moment). Once his master became ill and on his death bed he told choi to return to Korea for safty reasons. When he returned he opend his own club as he studied other martial arts and began to teach them in his school. Choi wanted to take the best of all the styles he studied. He took the kicks from TKD throws from judo and the joint locks from jujitsu. he also took more from other styls. He worked them in to finaly evolve in to hapkido. However what seporates Hapkido is the the cane tectiqus taught at the high levels.