A Local Perspective on Life in Tsukuba, Ibaraki, Japan.

KAGAMI BIRAKI (鏡開き)- Breaking Open the Mirrors- a closer look at how and why the Japanese break open and eat the New Year`s Kagami Mochi rice cakes on January 11th

Ten days have passed since GANTAN (元旦), New Years Day. The round mochi rice cakes, which have been set in the family’s Shinto altar (kami-dana), in the alcove (toko-no-ma) of the Japanese style tatami room, or these days, on a book shelf, dresser, or counter-top, have become hard and dried out, cracked, and maybe even, if you check underneath, moldy. After all this time, they have also been able to absorb plenty of LIFE ENERGY from the Toshi-Gami-Sama (the God of the New Year) to whom these Kagami-Mochi were offered. It is traditionally believed that this energy can be transferred to anyone who ingests these Mirror Rice-Cakes (as literally translated). These days, however, most Japanese who keep the tradition of breaking up these flattish, round mochi cakes by hand or with a mallet, and eating them in O-zoni (soup), or O-Shiruko (a hot, sweet, azuki bean soup) do so out of tradition, and because it is fun and delicious.

Kagami-Mochi at small shrine in Tsukuba
 Kagami-Mochi at small shrine in Tsukuba 


Looking closely at this custom also sheds some light on Japanese culture and more importantly, traditional ways of thinking.

These days, the 11th of January has become the standard day on which to do Kagami-Biraki, which translated directly means OPENING THE MIRRORS, though, depending on the region, neighborhood, or household, it can take place on any day in mid-January (in my neighborhood the mochi is eaten on the 16 of January). In fact, originally, the mochi-breaking ceremony was held on the 20th day of the 1st month, until the third Tokugawa Shogun, Iemitsu, passed away on that date, and the day was changed to the 11th.

Small  shrine in Tsukuba
 Small shrine in Tsukuba 


The round rice cakes were shaped to resemble mirrors because mirrors have been revered in Japan since ancient times and are believed to be receptacles of the gods. You might have seen mirrors set up inside the main halls of a Shinto Shrine. For the New Year, a smaller mochi is usually placed on top of a larger one (on rare occassions there are 3 mochi cakes in a stack !). Sometimes the Kagami-Mochi are further embellished with significant decorations such as a citrus called a daidai (which is a homophone for generation after generation), a spread open folding fan (to symbolize the spreading of your seed), kelp (konbu), which is a near homophone to YOROKOBU (to enjoy). There might also be other plants (all with symbolic meanings) and folded red and white paper (to keep out impurities) used to decorate the mochi.

The reason the hard mochi is broken and not cut is that the SAMURAI avoided using the word CUT, as well as the symbolic action of cutting, especially around New Year’s. Thus a knife is not used, And, even though the Kagami-Mochi is BROKEN, the word WARU (割る), to break, was also avoided (the SAMURAI did their best to avoid being cut or broken!). Instead, an IMI KOTOBA (忌み言葉), a euphemism, is used: hiraku (開く) to open. And thus this custom came to be known as KAGAMI-BIRAKI (鏡開き) the OPENING OF MIRRORS, which sounds very auspicious.

This was originally a custom of the warrior class. But as is so common in Japan, whenever allowed to, the commoners quickly emulated the customs of the higher classes  made them their own. among the general populace.

Apparently, during the Edo Period, families of the class however, also placed and left New Year`s rice cakes on their armout and helmets, and in the case of the women- on their mirrors! This custom has not survived

These days Kagami Mochi ceremonies can also be seen at weddings and other happy occasions.

And a recent INNOVATION in Kagami mochi marketing has been to sell them in see-through form- fitting plastic packets so that the rice does not get mouldy. It is opened on the 11th and is as fresh as it was on the day it was made.

If you have been in Japan on the weeks leading up to O-Shogatsu you have surely seen them if you have been to a supermarket or convenience store.

I have also written a Tsukublog article about HANABIRA MOCHI, an unusal Japanese sweet which is eaten at this time of year- especially by practioners of the TEA CEREMONY:



  • Mamoru Shimizu says:

    Thanks Avi-san your nice article, I reconsider Kagami-mochi also looking down my belly, my own Kagami-mochi-bara with me more than 30 years (thinner thanTaiko-bara:太鼓腹:drum shape belly: Sumou wrestler).
    Thanks to our USUGATA-TV (薄型TV: Thin screen TV?), during this Osyougatsu we could put down a very cute Kagami-mochi in front of TV. It is so tiny and is plastic -covered we haven’t decide” To eat it or not to eat, that is a question” (Oh! I always quote this kind of phrase, one pattern! even I only know this one!).
    We don’t think it will sustain until Osyougatsu of lunar calendar, if so it will be lunatic even it is packed in plastic. To say honestly it existed until May in our home last year. The Kagami-mochi cried “May-day!! May-day!!” May-23rd was my birthday, but no relation.

    Sorewa-sateoki(閑話休題:to return to my subject)
    I like hard dried Kagami-mochi, if I got such one I would break it to tiny peaces and fry them, then I could get very hard Agemochi(揚げ餅:fried rice cake), with salt it will be very tasty, harder than usual Osenbei, Okaki or any other snacks except burned dry corn in Nepal.

    There is a farmer’s shop called Tonarino-Yasai(隣の野菜:Next door vegetable), just beside the entrance of Kokuritu-Kankyou-Kenkyusyo (国立環境研究所:National Institute of Environment, Near Nishi-Ohdori cross Root 354).
    In this shop you can almost always find very hard “Agemochi” made by local female farmer, around 350円 per one pack. It looks expensive, but you will find it proper for the taste. In summer there will be big delicious water melons etc., it is an interesting shop.

  • alice says:

    I heard of relatives decorationg kagami-mochi in the toilets. I was surprised and when I asked why, they replied that they are token of thanks of being taken care of (oswea ni narimashita) by the toilets. I could help chuckling at that thought. I wonder if they eat it, though I was shy to ask them. Has anybody done that and eat the kagami-mochi from the toilets?
    To Shimizu-san,
    That part of keeping your kagami-mochi till May is hilarious! Would it be moldy by then? So did you finally eat it?

  • alice says:

    Hi Avi,
    When does omochi throwing (omochi nage) take place?

  • alice says:

    Have you tried omochitsuki? Why is it that some do it before the New Year and some after the New Year?

  • Avi Landau says:

    Hi Alice! Thanks for the good questions. Mochi-Throwing Ceremonies ( MOCHI MAKI or MOCHI NAGE) have been taking place in Japan (as far as we know) since the Heian Period with the intention of both bringing on good fortune AND keeping bad energies away.Mochi-throwing would be held before completing the construction of a building ( at the roof placing ceremony- JOTOSHIKI), at the beginning of the year, and at the end of a variety of festivals and ceremonies. This involved some person(s) of eminence tossing small mochi rice cakes into a crowd which has gathered to try and catch some of the lucky rice cakes.
    Things are pretty much the same today regarding MOCHI MAKI.
    The most common way that people encounter such a ceremony these days is still at a neighborhood JOTOSHIKI ( roof setting ceremony for a new building). Along with mochi, other snacks and five Yen coins might also be tossed into the crowd.

    Some temples have mochi throwing events at the beginning of the year. I have written about such an event at ANRAKU-JI Temple in Joso City which I attended on January 3rd of this year. I will also go to a similar ( but much more exciting) event at the Tsukuba-San Jinja Shrine on February 10th and 11th ( Ko Shogatsu, according to the old calendar). I have also written about that one- its called the TOSHIKOSHI-SAI.

    These events are lots of fun but can get a little dangerous since O-Mochi is hard and heavy. If you are not alert you can get smacked in the face!

    Also the crowds can get over excited grabbing for the lucky goodies. Little kids or older people can be severely injured.
    In fact, in the 1950`s, I heard that more than 100 were trampled to death at a MOCHI MAKI event in Niigata Prefecture.

  • Avi Landau says:

    Hi Alice! Yes, I have been to mochi-making events ( MOCHI TSUKI). Many of them. In fact, it is because of the delicious, still warm, freshly pounded mochi served at the harbour-biraki party ( which I have written about) that I have added a few pounds onto my abdomen- giving me my very own MOCHI. Unfortunately, I ate about 5 pieces there, with various toppings- kinako ( soy bean powder) grated radish, soy sauce and nori, and sweet azuki beans. This is probably the equivalent of more than 10 bowls of rice! It all goes down so smoothly however that you dont realize it!

    Japanese might hold mochi making events at ANY time, but they are most common at the end of the year and the beginning of the year.
    Most Japanese eat mochi over O-Shogatsu ( New Year`s) and traditionally mochi was pounded on the 30th of the 12th month.

    I have a book (written in Japanese) called MOCHI TO NIHONJIN ( Mochi and the Japanese), and in it the author, Satoru Yasumaru, gives a list of mochi making events held by two different families. They pound mochi several times throughout year for various events.

    Many Japanese that you talk to these days might experience a real mochi pounding event once or twice a year ( if at all).

    Many families who do make their own O-Mochi now use a machine. This can be dangerous- one of my student`s grandmother lost her finger ( a pinky) in one of the contraptions !
    Also, using a machine deprives the event of the great symbolic significant ( for fertility ) expressed by pounding a concave mortar (USU)- representing the FEMALE, with a big hammer-like pestle ( KIINE)- representing the MALE.
    The machine just makes mochi.

    Have you ever experienced MOCHI TSUKI? Be careful not to eat too much!

  • alice says:

    Haha! What a vivid description of the mortar and the mallet!