He had an alibi for the Shinsengumi concerning the assassination of Ryoma SAKAMOTO and influenced researchers studying Shinsengumi, but is currently labeled as a self-proclaimed 'soldier' since his registration in manuscripts of Shinsengumi during that period was not confirmed.
坂本龍馬暗殺事件について新選組のアリバイを主張、後世の新選組研究家たちに影響を与えたが、新選組の同時代資料では彼の在籍を確認出来ず、現在では自称「隊士」であるとされている。