Three cups of different sizes are passed around the family one by one. The traditional order is from youngest to oldest. The cups are called sakazuki — they are only used for drinking Toso on New Years Day.
Toso is thought to wash away the poisons and disease of the previous year. It's often handed out by doctor's offices as a New Years gift to patients.
Toso has a strong, medicinal flavor. Ingredients include pepper, radish, rhubarb, cinnamon, ginger (amongst other herbal ingredients). Toso originated in China. The Japanese version has become milder over the centuries. The mixture consumed in China is far more potent.