"Zenzai" (sweet red bean soup with mochi)
"Kagami Biraki" is one of a traditional ceremony represents "Starting something new" or "Wish unlimited joy to the family".
People break the Kagami-mochi (the round rice cake) which was displayed for first tendays of the New Year, and eat them on January 11.
"Kagami" literally means "mirror" referring to full moon, harmony, and symbol of a peaceful family.
"Biraki" means "open" referring to starting something new on business or a life such as wedding.
"Kagami Biraki" is known as the performance on the event for celebrations not only the New Year such as official kick off event for the company or sports, wedding, and so on. In those cases, the sake barrel is used instead of Kagami-mochi.