mochitsuki
Mochi (もち, 餅) is a Japanese rice cake.
In Japan, it is traditionally made in a ceremony called mochitsuki (餅搗き). While eaten year-round, mochi is a traditional food for the Japanese New Year, and is commonly sold and eaten during that time.
In the traditional process of mochi pounding, steamed rice is mashed and pounded with wooden mallets in a mortar. The work involves two people, one pounding and the other turning and wetting the mochi. They must keep a steady rhythm or they may accidentally injure each other with the heavy mallets.