Koshin Shinko is the belief that you are born with three worms (called sanshi) inside your body, and that these creatures’ only purpose is to shorten your life so they can be free again.
Hatsu-yume is the first dream you have in the New Year. In Japan there is a saying: ichi fuji, ni taka, san nasubi, which means the luckiest dream you can have is of Mt. Fuji, the second luckiest thing to see in a dream is a hawk, and the third is an eggplant.
Musha-burui is that trembling with excitement, anticipation, and fear one has before engaging in a formidable task. It comes from the idea of a samurai going headlong into battle.