As a good luck offering, giant kagami mochi (rice cakes) around the size of round mirrors, are dedicated at shrines in hopes for good harvests, fertility, etc.

Steamed mochi rice is pounded by huge wooden mallets in a stone mortar and then shaped into large round cakes. The mochi is heavy enough (400-500 kilos) to require lifting with a forklift. Some shrines place the mochi on a mikoshi which is then paraded to the shrine. The following two videos show the ceremonies at Yasuzumi Shrine (安住神社) in Takanezawa-machi in Tochigi Prefecture and Atsuta Shrine (熱田神宮) in Nagoya, Aichi Prefecture.