In the spirit of Japanese New Year’s, my wife bought three of these things. Apparently, it’s a tradition to place these in the house. Then when New Year’s is over, we’d eat it.

Kagami mochi, made of rice harvested in fall of the same year, is thought to contain the pure spirit of rice and thus be possessed with toshigami, a yearly deity that is said to visit during the New Year’s period, bringing a good harvest and the blessing of ancestors, and the power of life, according to the Japan Kagami Mochi Association.

Japan Times