In recent years, Japanese summers are often referred to as "extreme" or “intense.” To stay as cool and comfortable as possible, our ancestors devised various ways to cool off, such as using wind chimes, sudare (bamboo screens), gyozui (running water), and uchimizu (sprinkled water). Today, air conditioners and fans are the mainstream.

However, if the body is too cold, it can start to have an effect on the nervous system, and when the balance is lost, the body's resistance to the cold weakens, resulting in such symptoms as cold feet and legs, headaches, lethargy, or insomnia. This effect on the body is sometimes referred to as "air conditioning sickness.”

While making good use of air conditioners and fans, there must be other ways to relieve the heat. How about simply wearing clothes that keep you cool? In this blog, I will focus on three key points and introduce our samue and jinbei that do just that.

Point 1 : Choosing Well-Ventilated Clothing

Good ventilation is essential for comfortable and refreshing clothing in the hot and humid summer. Wasuian's lineup of summer-oriented items includes many fabrics with an uneven texture called "Shibo." Let's take a look at a fabric made of 100% ramie (hemp), a material with high thermal conductivity that is particularly cooling among natural fibers.

Enlarged image of Omi Chijimi ramie fabric (Dark Navy)

The weft yarns are woven with a strong twist and then untwisted by hand to create wrinkles called “Shibo” in the warp direction. This unevenness reduces the surface in contact with the skin and allows for better ventilation.

In addition to Omi chijimi, shibo is produced using various other techniques such as Ojiya chijimi, Shijira-ori, sucker-ori, and Yoryu. It may be said that these techniques are the result of a desire for comfort in the humid Japanese summer. (Please refer to each item page for an explanation of the characteristics of each "shibo".)

Point 2: Choosing a Cool Shape

Let me now turn our attention to the "jinbei," a traditional Japanese summer garment. Unlike samue, which has long sleeves and long pants, jinbei has short sleeves and pants that go below the knees, making it look cool as well as cool to wear in summer. Sleeves of Wasuian's jinbei are hand-knitted with kite strings, a rare type of jinbei that has been hard to find in recent years.

7060 Cotton Shijira Jinbei (No.1 Navy)

The kite strings from the sleeves to the sides are knitted by Japanese artisans one by one. Of course, it takes a lot of time and effort, but compared to other jinbei that only have simple lace sewn on, the high-quality appearance is worlds apart, and the cool breeze can pass through. It is said that "creative clothing" is important to prevent heat stroke, so we recommend these cool jinbei as perfect summer clothing.

7080 Washi Shijira-ori Jinbei (No.3 Green)

If you are not comfortable showing your knees, we also have samue that allows you to roll up the sleeves of the jacket and the hem of the pants. The rolled-up sleeves and hem can be fastened with buttons, so there is no need to worry about the sleeves or hem falling down after a while.

8050 Linen-Cotton Roll-Up Samue (No.1 Beige)

Point 3: Choosing Cool Materials

When you pass by a bedding department in early summer, you may see catchphrases such as "cool to the touch.” This is because many people will feel they should try it in the summer. The same can be said for clothing.

As I mentioned earlier, ramie (a high-quality kind of hemp) is said to be the number one natural fiber for cooling properties due to its high thermal conductivity. It is characterized by its excellent breathability and quick moisture dissipation, so it can be worn any time of the year without feeling dry. The fabric is also firm, so it does not stick to the skin.

1095 Omi Chijimi Honasa (Pure Ramie) Samue (No.95 Green)

In addition to ramie, Wasuian has products made from cotton-ramie, which has both the crispness of hemp and the feel of cotton, "Ice Cotton," a natural high-performance cotton material born from ultra high-twist technology, " COOLMAX® seersucker," a high-performance polyester fiber that always feels dry due to its fiber structure, and standard cotton which does not feel clammy but is highly absorbent. There are also products made from thin cotton, which doesn’t have a strong cooling effect but does have high sweat absorbency. You can choose according to your preference and purpose.


In this blog, I have discussed three points: good ventilation, cool shape, and cooling materials. Please consider "wearing cool clothing" as one way to alleviate the heat.