Kagami Biraki is a New Year’s celebration in Japan, usually celebrated around the second week-end of the year. Kagami Biraki is associated with samurai culture and this is why some traditional dojos have adopted aspects of the ceremony as part of their own New Year’s celebrations, focusing on self-reflection leading to new commitment.
The term ‘Kagami Biraki’ has several translations. Kagami refers either to a mirror or to mochi, a type of rice cake. Biraki is usually translated as “opening” or “breaking.” Taken together they translate as “Opening the Mirror” or “Breaking of the Mochi.” They also refers to the opening of a cask of sake.
The different items used in Kagami Biraki celebrations are powerful symbols. Mochi has a long, storied history in itself and is associated with the mirror because of the resemblance to the copper mirrors used in the past. The mirror also has a long tradition in Japanese culture and is linked to the sun goddess, Amaterasu. The mirror encourages insight through self-examination, which should lead to rededication.
In addition to mirrors, mochi, and sake, traditional symbolic elements include: citrus, usually tangerines in the US, symbolizing generational ties; salt for purifying; pine boughs, a symbol of longevity; armor, swords, helmets, and more. Some of these relate back to pre-samurai culture and some are shared across many cultures; for example evergreens, swords, and salt.
Kagami Biraki is a time for self-examination and the re-dedication of spirit and discipline toward training supported by our community.
More can be found here:
http://www.shitoryu.org/heritage/kagami_biraki.htm
http://www.aikidoda.org/aikidowebpages/seminarpdf/kagamidoc.pdf
http://classicbudoka.wordpress.com/2011/01/03/kagami-biraki-in-the-dojo/