Do you know why there is ushinohi; The day of U(shi) in Japan?
Hirai Gennai came up with this idea. He was a multi-talented man; horticulturalist, writer, inventor, painter and copy-writer. In other day, a eel seller asked him that “Do you have any strategy to sell hot foods (eel) in hot summer?” . Then, Hirai said to the seller “How about post a paper; TODAY IS THE DAY OF U (shi [=ox]→ unagi)?”. The sign reminded people the common sense of eating “u-foods” to help them beat the heat. And people thought “Let’s eat unagi!”
Indeed, scientific data shows that eel has vitamin B, which effective to overcome hot summer.
So if you like eel, I recommend you to eat eel the day of U! In this year , the date is July 21th.