one's first campaign;  one's first battle
(arch.)  crowning a boy for the first time at a coming-of-age ceremony;  noh cap with a rolled or drooping tail (indicative of nobility)
(arch.)  crowning a boy for the first time at a coming-of-age ceremony;  noh cap with a rolled or drooping tail (indicative of nobility)
 innocent;  naive;  artless;  unsophisticated;  pure;  fresh
 for the first time;  first thing;  doing something for the first time;  first menstruation