Nanakusa - the seven herbs or grasses.
-Haru no nanakusa are the seven herbs of spring; seri (Japanese parsley), nazuna (shepherd's purse), gogyo (cutweed), hakobe (chickweed), hotokenoza (henbit), suzana (turnip leaves) and suzushiro (garden radish leaves). Traditionally these seven herb are eaten in soup called nanakusagayu or rice gruel on the seventh day of the New Year to ward off disease in the coming year. Since the Meiiji period, on the morning or night before of January 7, people place the nanakusa, rice scoop, and/or wooden pestle on the cutting board and, facing the good-luck direction and chant , chant while cutting the herbs into pieces. Some areas substitute a different local herb for the soup and the chant varies but usually contain stories about the pursuit of either "the bird from the land of China" or "the evening bird." This day is usually called nanakusa no sekku (feast of the seven herbs).
This custom is a left over from an older custom called Jinjitsu (human day), which originally came from China, particularly the Hopei and Hunan regions of China, 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: on this seventh day, no punishments were handed out to criminals. The custom of eating the seven grass soup on jinjitsu spread in the Heian period. In the Edo period, on the morning of this day, it became customary for those under the Shōgun to eat the seven grass soup and then the assembled lords would enter the castle and address the Shōgun. Today, the events of jinjitsu are centered upon making and eating soup containing seven varieties of grasses in it.
-Aki no nanakusa are the seven grasses of autumn; hagi (Japanese bush clover), obana (flowering eulaia), kazu (pueraria), nadeshiko (wild pink), ominaeshi (patrinia), fujibakama (eupatorium), and kikyo (althea). The seven flowers are all indigenous
to Japan and are chosen for their flowers which bring out the atmosphere of the season. These are represented in Japanese art and literature fairly often, for example they show up in Manyoshu (the earliest collection of poetry and song), the Kokinshu (a later collection of poetry) and The Tale of Genji (an eleventh century novel considered to be the first modern novel). Unlike the herbs of spring these are not generally eaten (though some are/can be) and there is no specific day given to them. Though they are generally displayed on Tsukimi.
Tsukimi is a moon viewing party held on August 15th in the lunar calendar or sometime in September or October on the solar calender. Like many things, this custom originated in China from Zhongqiu Jie (the mid-autumn festival - Chinese calendars second most important holiday). Traditionally in Japan, tsukimi dango (dumplings), satoimo (taro potatoes) and Japanese sake are placed on a tray and grasses are arranged in a vase as an offering to the moon. People view the moon quietly at home, parks, shrines, temples, and so on. Various Shinto shrines do various things like have tea ceremonies, dances, poetry readings and music performances.