The twelve-year cycle
Eto assigns each year to one of twelve animals in a fixed sequence — rat, ox, tiger, rabbit, dragon, snake, horse, goat, monkey, rooster, dog and boar — repeating on a 12-year cycle. A person's birth year animal is treated as a small piece of personal identity in the same casual way a Western star sign might be.
Where it shows up around New Year
Shrine goods, New Year greeting cards and seasonal decorations around Osaka pick up the coming year's zodiac animal heavily through December and January — look for it worked into the design of omamori charms and other shrine items sold during the New Year period.
A small, easy cultural note
Knowing which animal a given year belongs to is a small but genuinely useful piece of context if you're visiting a shrine or department store around New Year and notice the same animal motif appearing on everything from sweets packaging to decorative charms.