K-3B's Washi Paper Business T-Shirt, Born from Ishikawa Textile Technology, Reaches Goal in 20 Minutes on Makuake, Surpasses 2 Million Yen Next Day

Kajinylon Co., Ltd. (Headquarters: Kanazawa City, Ishikawa Prefecture; President: Masataka Kaji) has announced that its wear brand "K-3B" has launched a project for a high-performance business T-shirt made with traditional Japanese washi paper yarn on the support-purchase service "Makuake," and has achieved its funding target.

This product was developed for Japan's increasingly severe summers, employing a uniquely developed material that combines traditional washi paper yarn with polyester. It is a shirt that solves the summer stresses of modern businessmen, such as sweat stains, odors, UV rays, and the daily hassle of ironing, starting from the material itself.

In tests at the Kaken Test Center, the fabric recorded 95% deodorization in 2 hours and a UV blocking rate of 99.4%, demonstrating overwhelming water absorption and diffusion properties surpassing 100% cotton. Supervised by Creative Director Yoshimasa Hoshiba, who describes it as "the optimal solution for adults, obsessed with silhouette and material precisely because it is the simplest and leaves no room for deception," this is a Made in Japan product with all processes from circular knitting to sewing completed domestically.

K-3B's First Makuake Project

Making Japan's Summer Comfortable, Starting from the Material.

In recent years, Japan's summers have become increasingly severe.

In business scenes, many people spend their time with various worries such as sweat, odor, UV rays, and the hassle of daily care.

K-3B chose to address this discomfort not by "adding functions later," but by rethinking the material itself.

The material adopted this time is a uniquely developed fabric combining traditional Japanese washi paper yarn and polyester.

In addition to the excellent skin separation characteristic of washi paper, it offers deodorant, quick-drying, and UV-cut properties, developed as a high-performance material suitable for Japan's climate.

Washi Paper Deodorant Business T-Shirt: Regular Price ¥9,900, Makuake Super Early Bird Price (limited first-come, first-served, 15% OFF): ¥8,415

A plating structure with washi paper yarn on the skin side and polyester on the outer side, balancing the comfort of natural material with practicality.

Washi Paper Deodorant Business T-Shirt (WHITE)

Main Functions Provided by the Washi Paper Material

- Deodorant performance
- Reduced sweat stains
- UV cut (99.4%)
- No ironing required
- Machine washable

■ Tested by Kaken Test Center
- Deodorization (isovaleric acid): 95% removal in 2 hours, maintaining 92% after 10 washes
- UV cut: UV blocking rate 99.4% (JIS L 1925)
- Sweat stain diffusion: Quickly diffuses sweat, making stains less noticeable

Developed with the aim of reducing summer stresses in modern business scenes, such as sweat stains, odor, UV rays, and ironing hassle. It employs a hybrid material (plating jersey) of washi paper yarn and polyester, uniquely developed by the Kaji Group, and is a functional Made in Japan T-shirt with all circular knitting, dyeing, and sewing completed domestically.

Original developed fabric leveraging the characteristics of washi paper, honed in Japan's hot and humid climate.

■ Comparison of K-3B washi paper yarn fabric and general 100% cotton fabric. The difference in diffusion speed after 20 minutes from a state containing the same amount of moisture can be observed.

■ Immediately after wetting (0 minutes)

Comparison of washi paper yarn fabric and general 100% cotton fabric. The state immediately after containing the same amount of moisture.

■ After 20 minutes

The washi paper yarn fabric quickly diffuses sweat. The difference after 20 minutes changes the comfort of the day.

■ Related Person Comment

Mr. Yoshimasa Hoshiba

K-3B Creative Director Yoshimasa Hoshiba recommends this product.

"I thought this was the 'optimal solution' for summer business scenes."

A white T-shirt is the simplest and leaves the least room for deception. That's why I believe silhouette and material are crucial.

This T-shirt was supervised with a focus on a balance that looks beautiful as an inner layer for a jacket. It aims to work as a standalone piece while looking neat when a jacket is worn over it.

Combined with this is the Kaji Group's washi paper material. It offers good skin separation even when sweating, and excellent deodorant and quick-drying properties. Considering the current intense heat in Japan, I think it has become a very reliable piece for summer business scenes.

It's comfortable yet looks properly elegant. I feel this is the kind of manufacturing unique to Japanese textile manufacturers.

Washi Paper Deodorant Business T-Shirt, Size 1(M) worn

■ Profile of Yoshimasa Hoshiba

After working for men's magazines "LEON" (Shufu to Seikatsu Sha) and "OCEANS" (currently Lighthouse Media), he became independent in 2010. Since 2015, he has served as the editor-in-chief of the web magazine "Forza Style" (Kodansha).

Project Name

K-3B | A Business T-Shirt Made of Washi Paper, Born from Ishikawa's Textile Technology

Start Date and Time

June 4, 2026 (Thursday) 12:00 PM

Goal Achievement

Achieved in 20 minutes after launch

Total Support Amount

¥2,069,991 (as of 10:00 AM on June 5)

Number of Supporters

191 people

Super Early Bird Price (limited first-come, first-served)

¥8,415, 15% OFF (Regular Price: ¥9,900)

Listing URL

https://www.makuake.com/project/k3b-washi-tshirt

Recruitment Period

Until 10:00 PM on June 18, 2026 (Thursday)

■ Product Overview

Product Name: Washi Paper Deodorant Business T-Shirt

Blend Ratio: Polyester 85% / Washi Paper 15%

Colors: WHITE / BLACK

Sizes: 0(S) / 1(M) / 2(L) / 3(LL) / 4(3L)

Country of Origin: MADE IN JAPAN (all circular knitting, dyeing, and sewing domestic)

■ K-3B Official Shop List

- K-3B OMOTESANDO HILLS
Location: Omotesando Hills B3F (4-12-10 Jingumae, Shibuya-ku, Tokyo)

- K-3B GINZA SIX
Location: GINZA SIX 5F (6-10-1 Ginza, Chuo-ku, Tokyo)

- K-3B DAIMARU TOKYO
Location: Daimaru Tokyo Store 11F (1-9-1 Marunouchi, Chiyoda-ku, Tokyo)

- K-3B FLAGSHIP SHOP
Location: KAJI FACTORY PARK 2F (102-1 Osaki-o, Kahoku City, Ishikawa Prefecture)

- K-3B Official Website: k-3b.com

■ What is K-3B?

A hyper-rational setup brand launched by Kajinylon Co., Ltd., a textile manufacturer headquartered in Hokuriku Ishikawa, a major synthetic fiber production area, with Creative Director Yoshimasa Hoshiba. Established in April 2020. It is the ultimate hyper-rational setup that strips away all waste, equips only necessary functions, and even eliminates the wasted time of coordinating outfits. In 2023, a WOMENS line was also introduced. k-3b.com

▶ Functionality through Materials

K-3B materials use the Kaji Group's synthetic fiber fabric brand "KAJIF." Its appeal lies in functionality that maximizes the strengths of synthetic fibers, such as easy-to-move, comfortable stretchability and water repellency resistant to rain.

*What is KAJIF?

KAJIF is a brand of quality functional synthetic fibers that advocates sustainability beyond just the environment. For the continuation and development of Japan's textile industry.

World-class textile technology