The Japanese have a custom of eating eel in the middle of summer, especially on 'Touyoshi Day,' when the amount of eel sold is several times the amount sold on a normal day, and this is a tradition that continues every year.
There are many different explanations for the origin behind this custom. One of the most famous is the Hiraga Genuchi theory. It is said that one summer, when eels were not on sale, the owner of an eel shop, who was worried about this, approached Hiraga Kennai and asked him to help him think of a solution. Hiraga Genuchi thought for a moment and told the eel shop owner to put up a sign at the front of the shop saying: 'Today is Ushi Day, and Ushi Day is the day of the eel, so if you eat eel on this day, you will be able to live in peace for the rest of the summer.' The eel shop owner did as he was told, and the eel shop's business really turned around and prospered. Other shops saw this and imitated it. As a result, the custom of eating eel on Touyoshi Day in summer has been fixed and continues to this day.
The next story is the 'Ota Shuzanjin Story', which is similar to the 'Hiraga Genuchi Story'. In this story, a scholar named 'Ota Shusanjin' was asked to write a sign saying 'Eat eel on this day and you will be free from illness and disaster for a year' and hang it in the shop to attract customers in order to help the eel shop owner to increase the sales of eel. In addition, there is also the 'Kasugiya Sermon'. Harukiya is an eel shop located in Kanda, Edo. It is said that during the Genroku period (1688-1867), the Fujiedo family ordered a large quantity of kabayaki eel from Kasugiya. In order to store the eels, Harukiya puts them in a clay jar and hides them in a cave on the days of Toshi, Ushi, and Tobayashi. Miraculously, only the eel on the day of Ushi did not spoil, and the flavour of the eel remained intact. This is the origin of the custom of eating eel on the day of Ushi.
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