Jinjitsu

Jinjitsu, which is Japanese for “Human Day”, is the first of five seasonal festivals, known as gosekku.

According to the wikipedia article on the festival:

“The name comes from an ancient Chinese custom Renri, whereby each of the opening days of the first lunar month was assigned to a particular creature, which it was forbidden to kill on that day: thus the first seven days of the month were Chicken Day, Dog Day, Boar Day, Sheep Day, Cow Day, Horse Day, and Human Day”

Today, Japanese people eat a rice porridge consisting of the seven wild herbs of spring known as nanakusa-gayu. Traditionally, the seven herbs are water dropwor, shepherd’s purse, cudweed, chickweed, nipplewort, turnup, and daikon. Today, the ingredient list varies widely, as common local herbs are often substituted.

There is a recipe for nanakusa-gayu on the blog Blue Lotus.