Kagami Biraki: Open Up to Good Fortune ~ Part 2

We continue with our discussion about Kagami Biraki and how it is celebrated in Japan. As mentioned in part 1, this ceremony has important ties with the martial arts community. Yet, it is but only but one part of the overall experience, as there are other manners in which people can acknowledge this without having to be a martial artist. In this article, we will take a brief look at the origins of Kagami Biraki, and how it is observed by the general public, both on an individual level and in a public setting.


Sometime in the Edo period, Kagami Biraki originated through strong roots to buke (武家), or military families. According to resources such as “Nihon Kokujo Daijiten” (日本国語大辞典) and “Nihon Daihyakka Zensho” (日本大百科全書), the original date was set for the 20th day of the 1st month, but was then changed to the 11th day due to the 3rd Tokugawa shogun Iemitsu passing away on the 20th of the 4th month in 1651¹. Some references still remain concerning the original date. For instance, In Japanese the 20th day of the month is pronounced hatsuka (二十日, 20 days). To tie it in with their heritage as warriors, the characters of hatsuka were changed to “刃柄”, which can mean “sword”, as the characters reference a blade and a handle.

To celebrate, men would have mochi set up before a fine suit of armor. Not only was this mochi called “gusoku mochi” (具足餅, armor mochi), but the ceremony itself was once called “Gusoku Biraki” (具足開き) or “Gusoku Kagami Biraki” (具足鏡開き). On the other hand, for women of these same families, they would instead setup the kagami mochi on a kagami dai (鏡台), which is a small platform where a mirror would normally go on. As a play on words, women also referred to the original 20th day as “hatsukao” (初顔) or “hatsukagami” (初鏡). This points to them seeing themselves in the mirror the 1st time of the new year and admiring their beauty.

For either manner, these families followed a belief about inviting the toshigami (年神) into their home through the use of a kadomatsu (門松, paired decoration of pine and large bamboo shoots) within the first week of the new year². Shortly after this, they would further wish for luck from the toshigami presently residing in their home through eating kagami mochi (鏡餅), which is a 2-tier rice cake that is slightly firm on the outside, yet soft on the inside. For public events, the kagami mochi is often very large, and may be in the familiar 2-tier shape or separated. Normally a powder white color, in some events the top mochi may be dyed pink. For those occasions where the presentation is simpler, the kagami mochi is much smaller, and placed on a kagami dai.

To the right, a decorated kagami mochi placed on a kagami dai. From AC-Illust.

To consume a kagami mochi, the standard practice is to first split the top layer, then separate it. People can do this by hand, or with a small wooden mallet. Spreading it open in this fashion is symbolic as one’s fortune growing ever so widely. This action is usually described with the phrase suehirogari (末広がり), which stands for opening up like a folding fan called a sensu (扇子). This phrase is one of the reasons why a small sensu is used dress the kagami mochi. There are other terms used to describe Kagami Biraki, as well as how one goes about conducting this ceremonial-like practice, but the above one is currently the most recognized one.


In terms of general observation, there is “Kagami Biraki no Hi” (鏡開きの日, Kagami Biraki Day). While it is officially appointed on the 11th day of January, there are other dates depending on which part of Japan a person is from. On whichever day it falls on, the general population may choose to consume a treat that is believed to promote longevity and good luck. These treats usually consist of mochi in it. A few examples are the following:

  • kinako mochi (きな粉餅, roasted soybean powder-covered mochi)
  • age mochi (揚げ餅, deep fried mochi)
  • yaki mochi (焼き餅, roasted mochi)
  • kurumi mochi (くるみ餅, mochi covered in grounded walnut sauce)
  • oshiruko (おしるこ, sweet redbean soup)

Note that these can be eaten regularly anytime one feels like it, but tend to be chosen as the to-go choices on Kagami Biraki no Hi. From my personal experience, kinako mochi is a great treat on it’s own or, following popular trends, with green tea. It’s especially tasty with kuromitsu (黒蜜, brown sugar syrup). Yaki mochi is another that I’d generally eat on Kagami Biraki no Hi, as it is simple to prepare. Wrapped in nori (のり, roasted seaweed), it has a good crunch, while dipping it into soy sauce enhances the flavor.


As one would imagine, Kagami Biraki has a connection with religious establishments. As an example, priests of either Shinto or Buddhism perform rituals that are meant to ward off any serious natural disasters and plagues, which is still in practice today. Also, kagami mochi and other forms of charms are sold at the stalls that are set up on the grounds around shrines and temples, readily available for purchase by visitors. Another example is the symbolic use of taruzake (樽酒), or rice wine sealed in special barrels, as part of the ritual at a shrine. This rice wine is considered to be goshinshu (御神酒, divine wine of the gods), and is viewed to bring luck in the same manner as kagami mochi. In fact, the round lids are split open with a small wooden hammer. It is thought that the practice with the taruzake predated the kagami mochi, thus inspiring this common practice that anyone can do even at home.

A pic of taruzake. From AC-Illust.

Note that both kagami mochi and taruzake have a lot in common regarding how they are used during the ceremony Kagami Biraki. The round shape of the mochi and the lid of the barrel represent a “mirror”, and when “split open”, good fortune is spread out for each individual. Note that a small wooden hammer is the preferred method for bringing forth good luck. A few things to consider are their differences, such as that the term kagami biraki is used to indicate to splitting of the kagami mochi, but not for the splitting of the lid on the taruzake, despite it being used in the same event. Instead, the proper term for the action done on the taruzake is “sakedaru wo akeru” (酒樽を開ける), or even “shito wo akeru” (四斗樽を開ける).

An interesting point worth mentioning is the evolution of the name Kagami Biraki. While it did bear different titles from conception to the change of the designated day, there are 2 that are important in relations to the tone of this ceremony. It is thought that at one time in the past the name used for celebrating with kagami mochi was “Kagami Wari” (鏡割り), for a knife was used to slice open the mochi. For taruzake, “Kagami Biki” (鏡引き) was used to indicate how the lid was pulled off of the wine barrel. Due to unfavorable implications presented by both names, a more acceptable concept to highlight what the ceremony was meant to achieve helped to have both replaced by the title “Kagami Biraki”. If we look at Kagami Wari, the idea of using a knife to cut open something was reminiscent to seppuku (切腹, suicidal cutting of one’s belly), which contradicted with the idea of a ritual that was to bring luck. As for Kagami Biki, using a pulling force also did not fit well when it comes down to wishing for luck. It boils down to the idea that both kagami mochi and taruzake inhabited by new year lucky deity spirits³. Using a sharp instrument, or a physical pulling action, resemble an aggressive attack on these deity spirits with which people seek good fortune from. Thus, using a hammer to merely split the top layer was viewed as the proper method for releasing good fortune from within.


From its history down to the different manners in how it’s celebrated, we get a feel of how deeply entwined Kagami Biraki is with the Japanese culture. While instilling the ritualistic idea of wishing for longevity and good fortune, it is approached in a fun manner with the inclusion of sweet treats. This covers the overall observation of Kagami Biraki. Looking forward to public gatherings for this in the future once the world can get back to normal.

1) Note that is is according to the inreki (陰暦), or old calendar system once used predominantly in Japan. This means that, in comparison with the modern, Gregorian calendar, the inreki was late by one month. So, the 1st month of the new year would’ve actually been February.

2) The standard time in modern times is from January 1st to January 7th, although it may start as early as December, or end as late as January 15th, in certain areas of Japan based on their tradition. This period is called Matsu no Uchi (松の内), which stands for inviting the toshigami inside one’s kadomatsu.

3) Other than the toshigami, deities of rice such as inadama (稲魂) and kokurei (穀霊) were thought to inhabit the kagami mochi and taruzake. Thus the quality of these items, as well as the proper means of showing respect when opening these items, is important.