The Wikipedia entry goes on to say: Masahiro Morioka argues that Japanese herbivore men are a result of Japan's post-war peace. Since the end of World War II,

The Wikipedia entry goes on to say: Masahiro Morioka argues that Japanese herbivore men are a result of Japan's post-war peace. Since the end of World War II, Japan has not directly participated in any war or conflict, either within its own borders or outside of them. Prior to this time of peace, many Japanese felt that becoming a soldier was the only approach to becoming manly. This social norm has slowly disappeared during the following period of post-war peace. Due to this, Japanese men are less aggressive and this could bleed over into their romantic lives.