Kagami-Mochi New Year Ritual and Mochi Preparation
Japan — Shinto and Buddhist New Year tradition, documented from Heian period
Kagami-mochi (鏡餅, mirror rice cake) is the round, stacked New Year's decoration placed on the tokonoma alcove or family altar from December 28 until January 11 (Kagami Biraki, mirror opening). The two-tiered stacked round mochi discs — a larger lower disc topped by a smaller one, crowned with a daidai bitter orange — represent the moon, the sun, and generational continuity. The ritual production of kagami-mochi involves pounding (mochi-tsuki) the stickiest short-grain glutinous rice (mochigome) in a large wooden mortar (usu) with a heavy wooden mallet (kine) — a community and family ritual performed on December 28 (the 29th is considered unlucky for pounding as 'ku' means suffering; the 31st is too rushed, a one-night decoration). Traditional mochi-tsuki involves alternating between pounding and folding: one person pounds while another quickly folds the paste between blows — extreme coordination required. After the pounding reaches the desired sticky, smooth consistency, the kagami-mochi are formed by hand into rounds while still warm, placed on clean washi paper. On Kagami Biraki (January 11), the hardened mochi are cracked open (never cut — cutting is samurai terminology; the hammer crack is the correct approach) and the pieces are boiled in ozoni soup or toasted as yakimochi, eaten to receive the New Year's luck stored within.