Up to a certain age, gender’s really not too important.
Otoko no ko means male child, and onna no ko, female child.
I had to look up earthworm: mimizu
I usually get along very well with people of all sorts, but it struck me the other day that since about the age of twelve, I haven’t associated with boys in the same way as with girls, in fact, it’s been two whole years since I last worked and hung out with a guy. I think I must recitfy that! Dunno exactly how yet, since my circles right now are very much girls only, but I’ll definitely have to give it some serious thought. 😉