Here is the information we learned from Sensoji Temple in Asakusa. Avoid disaster or grant protection, there are a wide variety of divine charms called 'omamori' sold at various temples and shrines all across Japan. The handling of such a token--a symbol of a god's divine power--must be done with special attention.

An Omamori from Sensoji Temple (Asakusa Kannon) in Tokyo is a sacred Japanese amulet or "good luck charm" believed to provide protection or various forms of blessings to the holder. These amulets typically consist of a small, colorful silk pouch containing a consecrated piece of wood or paper with a Buddhist prayer or sacred symbol inscribed upon it. At Sensoji, one of the most famous temples in Japan, you can find a wide variety of specialized Omamori, including those for Traffic Safety (Kotsu-anzen), Academic Success (Gakugyo-joju), Good Health (Kenko), and Warding off Evil (Yakuyoke). A unique Sensoji-specific talisman is the "Silver Charm" or the "Lotus Charm," which features a depiction of the Kannon Bodhisattva. Tradition dictates that you should never open the pouch, as doing so is believed to release the charm's spiritual power and render it ineffective. It is customary to carry the Omamori on the outside of a bag, in a wallet, or hanging in a car. Most people keep their Omamori for one year, after which they return it to the temple to be ritually burned in a "Kuyo" ceremony, and then purchase a new one to renew their protection and luck for the coming year.