Shobuyu : The Sweet Flag Bath for “Tango no Sekku” Festival on May 5

A few days ago, I posted an article about Kashiwa Mochi. “Kashiwa Mochi (柏餅)” is a traditional Japanese sweet for “Tango no Sekku (端午の節句)”, the Boys’ Festival held on May 5 in Japan. Tango no Sekku is also referred to as Children’s day in English.

Shobu-Yu (菖蒲湯) : Japanese Sweet Flag Bath

The day, May 5 is a Japanese national holiday to celebrate and wish boys’ healthy growth and happiness, when we Japanese have a traditional custom. The tradition is to take “Shobu Yu (菖蒲湯)”, or having a sweet flag bath.

The Origin of Shobuyu

Shobuyu Sweet Flag Bath

The Japanese tradition of taking a sweet flag bath on May 5 has a long history. It is said that Shobu-yu originated from China, and in the Edo period (1603 – 1868), the common people came to take the sweet flag bath.

Actually, the Japanese word meaning sweet flag, “Shobu (菖蒲)” has another Chinese character pronounced in the same way “Shobu (尚武)”, and the Japanese term, “Shobu (尚武)” means to consider Japanese martial arts and military “Budo (武道)” as an important thing.

Since “Shobu (菖蒲)” has the same reading as “Shobu (尚武)”, the people at that time came to use the plant for bathing on May 5 in the hope of what the word “尚武” means.

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

From the above, the traditional custom, taking a Shobuyu on Tango no Sekku has been handed down to this day in Japan.

How to Make Shobuyu


The making method of Shobu-yu depends on each household, but in many cases, just add sweet flag leaves to a bathtub of hot water.

Health Benefits of Shobu-Yu Sweet Flag Bath

The plant, Shobu contains various essential oil components, such as Asarone and eugenol, so you can expect the effect of relieving neuralgia and backache from Shobu-yu. What is more, the sweet flag bath has a distinctive aroma that helps you relax.

(Reference page of this article : Wikipedia 菖蒲湯 )


Hi, I'm Tomo, a Japanese blogger living in Niigata Prefecture, Japan. I want to introduce things about Japan on this blog, especially unique Japanese products, cooking recipes, cultures and trivia.

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