Herbivore men was coined by Maki Fukasawa and was a negative connotation as as young men who had lost their "manliness" and were responsible for Japan's declining birth rate which is actually due to high life expectancy and low fertility rate  among other things.
The term was coined by the author Maki Fukasawa, who initially intended for it to describe a new form of masculinity that was not reliant on the proactivity and assertiveness typically associated with masculinity in Japan. The term was quickly sensationalized by the media, gaining a negative connotation as young men who had lost their "manliness" and were responsible for Japan's declining birth rate and stagnating economy. The dramatic aging of Japanese society as a result of sub-replacement fertility rates and high life expectancy is expected to continue. 
