OHASHI, who was engaged in the Sakashita Mongai Incident, was arrested on February 13, 1862, and Umunosuke, who was not involved, came under suspicion as a pupil as he hid himself at the residence of a friend of his.
文久2年（1862年）1月15日、坂下門外の変に関係した大橋が捕縛され、無関係であった有無之助自身も門弟として嫌疑をかけられたため知己のもとへ身を隠す。