Sadakichi KITA (a historian of modern Japan) forms a conjecture that Sakahoko (a halberd placed upside down) was planted on the peak of Mt. Takachiho-no-mine by an ascetic Buddhist monk who, being prompted by "Jinno Shotoki" and the like, created the myth of the divine descent on Mt. Kirishima.
喜田貞吉は、『神皇正統記』などに触発され霧島山降臨の話を作り出した修験者が高千穂峰の山頂に逆鉾を置いたと推察している。