Shobuyu: Sweet Flag Bath for Boys’ Day on May 5

A few days ago, I posted an article about Kashiwa Mochi, a traditional Japanese sweet for “Tango no Sekku (端午の節句)” or the Boys’ (Children’s) Day on May 5. 

Shobuyu (菖蒲湯)

The day May 5 is a national holiday in Japan when we celebrate boys’ healthy growth and wish for their future happiness with a traditional custom. It is actually to have a sweet flag bath or “Shobu-Yu (菖蒲湯)”.

The Japanese tradition of soaking in a sweet flag bath on May 5 has a long history. It is said that Shobuyu originated from China, and in the Edo period (1603 – 1868), it became popular among common citizens.

Shobuyu Bath

The word “菖蒲 (Shobu)”, meaning “sweet flag” in Japanese, can also be represented as “尚武 (Shobu)” using Kanji Chinese characters, which means putting much value on martial arts and the military or “Budo (武道)”.

Since “菖蒲” has the same reading as “尚武”, people at the time began to use the plant for bathing on May 5 in the hope of what the word “尚武” stands for.

In fact, since the old days in Japan, the sweet flag Shobu has been believed to be a medicinal herb for driving away evil spirits.


Shobu Yu Sweet Flag Bath

The preparation of Shobuyu varies depending on each household. But in many cases, simply add sweet flag leaves to a tub of warm water.

Health Benefits

The plant Shobu contains essential oil components, such as Asarone and eugenol.

So from Shobuyu, you can expect the effect of relieving nerve pain and backache. What is more, as the leaves have a distinctive aroma, you will relax during the bath.

(Reference Page: Wikipedia 菖蒲湯 )


Hi, I'm Tomo, a Japanese blogger living in Niigata Prefecture, Japan. For the purpose of enriching your life, I would like to introduce things about Japan on this blog, especially unique Japanese products, cooking recipes, cultures, and facts and trivia.

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