Japanese culture, especially Shinto beliefs, are focused on the idea of purification. I talk about this aspect of Japan extensively in my Japanese Tea Ceremony vlogs. Check it out in the "Japanese Tea Ceremony" category to the right of this page. The idea of purification is one of the main reasons why the Ise Shrine is constantly rebuilt; to promote the freshness, the cleanliness, and the purity of the Shrine. Japan encourages the concept of constant renewal and recharging. This phenomenon applies to the omamori as well-- the "magic" is not permanent. It is a ritual for Buddhist and Shinto shrines to take in old omamori (old meaning as early as the previous year), and burn them, as if to get rid of any bad luck the omamori might have absorbed. It is common for omamori to be purchased around New Years to start afresh with new luck for the new year.
Stay tuned for tomorrow's post, where I will talk about my dad's experience at the Ise Jingu Shrine. :)
Until next time,
Tswei, Suzanne. "Omamori 'Critical' for Luck in New Year." Honolulu Star - BulletinDec 30 1999. ProQuest. Web. 15 July 2014 .