Herbivorous Men are men who outwardly show a disinterest in chasing women. This is taken from the representation of men as "predators" and women as "prey". A herbivore would not chase the prey and instead eat his vegetables with no care for pursuit.
The real irony here is that Sanae is a snake, and snakes happily eat herbivores...
And herbivores eat plants.
PopIt seems that Rinnosuke-san doesn't really try to eat up Reimu-san and them. Are you what they called an "Herbivore Men" kind of guy?Of course I meant that sexuallyHerbivore...That's so naughty...Grass AttributeI somewhat understand just how you look at me.