Can anyone tell me what the literal translation of Kagami Biraki is? Does it just mean Happy New Year?
"Kagami" means "mirror" and "biraki" is the noun form (with a "nigori" (vocalization) of the "h" to a "b") of the verb "hiraku" which means "to open."
"Kagami biraki" is a term often used in dojo and places of worship to refer to the "opening" of the place in the new year. It doesn't mean "happy new year" but refers to this tradition and ceremony of opening up the place for the new year. Often, we would break apart a piece of hardened mochi (rice cake) as part of this ceremony.
The term for "happy new year" in Japanese is "shinnen akemashite omedetou gozaimasu."
Hope that helps,