1.
breaking open of New Year's mochi
The traditional ceremony of breaking apart the round mochi that was offered to the gods during the New Year period, usually on January 11.
一月十一日に鏡開きをした。
We did the kagami-biraki on January 11.
鏡開きの餅でお汁粉を作った。
I made sweet red bean soup with the mochi from the kagami-biraki.
鏡餅は包丁で切らずに、手や木槌で割るのが正しい鏡開きの作法だ。
The proper way of doing kagami-biraki is to break the mochi with your hands or a wooden mallet, not cut it with a knife.
2.
opening a sake barrel at a celebration
The ceremonial act of breaking open the lid of a sake barrel with a wooden mallet at celebrations, weddings, or grand openings.
祝賀会で鏡開きが行われた。
A sake barrel opening was held at the celebration.
新店舗のオープンを記念して鏡開きをした。
We held a sake barrel opening to celebrate the new store's opening.
結婚式の披露宴で新郎新婦が一緒に鏡開きをする演出が人気だ。
At wedding receptions, it's popular for the bride and groom to do the sake barrel opening together.
Literally "opening the mirror," where 鏡 refers to the round, mirror-like shape of the mochi or sake barrel lid.
SENSE 1 — NEW YEAR'S MOCHI:
The 鏡餅 (round New Year's mochi) is displayed as an offering during the New Year period. On January 11 (or January 15 in some regions), it is broken apart and eaten. The word 割る (to break) is avoided because of its negative connotations; instead, the auspicious word 開く (to open) is used.
SENSE 2 — SAKE BARREL:
At celebrations, participants break open the wooden lid of a sake barrel (酒樽) using wooden mallets. This is a festive ritual at weddings, business openings, and victory celebrations.
COMMON COLLOCATIONS:
- 鏡開きをする: to perform kagami-biraki
- 鏡餅の鏡開き: breaking New Year's mochi
- 酒樽の鏡開き: opening a sake barrel
RELATED TERMS:
- 鏡餅: round New Year's mochi — the offering that is broken during the ceremony
- お汁粉: sweet red bean soup — a common way to eat the broken mochi
- 酒樽: sake barrel — used in the celebratory version