YAMAGUCHI had contributed an article of argument and consideration titled "Kick the parents" to Heimin Shinbun (Commoner's Newspaper) (No.59) in March 1907, severely criticizing the feudal family system.
山口は1907年3月、封建的家族制度を痛烈に批判する論考「父母を蹴れ」を平民新聞（第59号）に寄稿した。