YOKOYAMA recommended the son of Hisamitsu for traveling to study outside of the domain, and YOKOYAMA accompanied him to Saga and Yamaguchi regions; however, YOKOYAMA was involved with an incident during this trip that some members of the Kiheitai Army dropped out of the party, and when he went back to Kagoshima for reporting the incident without getting permission of his return, he was dismissed from his position by Hisamitsu.
そして久光の子に藩外での遊学を勧め、佐賀や山口に同行するが、その際奇兵隊の一部の隊士の脱退騒動が発生し、安武は騒動を報告するため無断で鹿児島に帰国したが、久光に免職された。