there are many factors around the herbivore trend in japan.
one of the foremost is the 'homosexual effect' that overcrowding has.
if you remember ra has explained that overcrowding in cities causes constant infringement on people's energy fields, causing them to react by developing homosexual tendencies. ra explains that if these people go to a less crowded location and live there, the desire to reproduce, therefore the red ray comes back again.
this seems to be an evolutionary/spiritual mechanism to prevent overcrowding.
however, if we turn to the herbivore trend in japan, its easy to see that it is at play there : japan is EXTREMELY crowded. probably there is no other country which is as crowded as japan. which would naturally not only push people away from other people, but also create this effect above.
not surprisingly there are herbivores in japan now, who are more feminine men - but still male, and probably most heterosexual - AND, there are carnivores - who are described as aggressive women. who are also reacting similarly to these factors it seems.
there are also other factors. herbivore movement also has a component of reaction to the 'work hard like a bee until you die from overwork or retire at age 70 with no time for yourself' format which has been pushed to japanese people through the capitalist system implemented by big industrialist families owning japanese economy. since 1950s.
these people dont want to work their lives off like their fathers. instead they want to do things they want, and pursue lives that would matter to them.