Hemp 100% T-shirt "HEMP Air" with Breathability, Moisture-Wicking, Antibacterial, and UV Protection for Japan's Hot and Humid Summer Available for Pre-order on Makuake Starting June 29 (Mon)

Project Name: Pursuing Coolness with 100% Hemp! A High-Performance Natural Fabric T-shirt Creating the Future of "Ordinary"

Campaign Period: June 29 (Mon), 2026, 11:00 AM – August 16 (Sun), 2026

Sales Platform: Makuake, a crowdfunding site for innovative products and experiences

Project URL: https://www.makuake.com/project/hemp-air/

Product Name: HEMP Air

Material: 100% Hemp

Sizes: XS–XL

Colors: Natural, Navy, Dusty Pink, Sage Green

Planned Retail Price: ¥12,100 (tax included)

YS International Co., Ltd. (headquartered in Tokyo), the company behind the natural-materials brand "tennen," will begin accepting pre-orders for its high-performance 100% hemp T-shirt "HEMP Air" via the crowdfunding platform Makuake starting June 29 (Mon), 2026. Since 2020, the company has offered hemp T-shirts and previously raised over ¥4.1 million in cumulative support through past Makuake campaigns. This new release marks the fourth-generation model, featuring improved fabric smoothness and enhanced functionality. Designed with the comfort of natural materials, the T-shirt also delivers key summer-wear features such as breathability, moisture-wicking, antibacterial properties, and UV protection.

▼ Makuake Project Page (Public from 11:00 AM, Monday, June 29, 2026)

https://www.makuake.com/project/hemp-air

Development Background: Offering Natural Materials for Japan’s Hot and Humid Summers

In recent years, summer heat in Japan has intensified, increasing demand for clothing with superior comfort. However, many functional summer undergarments and T-shirts rely on synthetic fibers, raising concerns about texture, lingering odors, and environmental impact.

In response, tennen focused on "hemp," a natural fiber long used in textiles.

Hemp belongs to the bast fiber family and is known for excellent breathability and a naturally dry, smooth feel even when sweating.

Compared to cotton, which requires large amounts of water and fertilizer during cultivation, hemp is recognized as a sustainable material with lower environmental impact.

Given its natural origin and potential for moisture-wicking and antibacterial performance, hemp was deemed ideal for summer T-shirts, prompting further development.

However, 100% hemp fabric is typically stiff and coarse, requiring advanced techniques to achieve comfortable everyday wear. To address this, tennen collaborated with a knitwear factory in Wakayama Prefecture to develop a fabric that maintains 100% hemp content while delivering a smooth, lightweight feel.

Product Features

1. Exceptional Breathability and Lightweight, Smooth Comfort

"HEMP Air" uses 100% hemp yarn to achieve a texture comfortable enough for daily wear. Hemp fibers have a hollow structure and countless micro-pores. This unique construction creates air channels, producing a natural coolness that synthetic fibers cannot replicate.

The knitting process preserves hemp’s characteristic crispness while ensuring a cool, refreshing touch against the skin—verified to have a contact-cooling effect. Even in humid, sweaty conditions, the fabric resists stickiness, maintaining a dry, comfortable feel.

2. Rapid Sweat Absorption and Evaporation: Superior Moisture-Wicking for Hot Weather

Discomfort during hot, humid seasons often comes from sweat-induced stickiness and fabric clinging.

"HEMP Air" passed the drop absorption test, with moisture absorbed on the fabric’s reverse side in just 4 seconds—well under the standard benchmark of 10 seconds. In the KAKEN rapid-drying test, it achieved 27.7%, surpassing the benchmark of 30% or less. Thanks to its ability to quickly absorb, spread, and evaporate moisture, the fabric minimizes stickiness and maintains a fresh, dry feel even when sweating.

3. Natural Antibacterial and Odor-Resistant Properties

During extreme summer heat, prolonged wear of T-shirts can lead to concerns about dampness, stickiness, and hygiene. Unpleasant odors and discomfort often stem not just from sweat itself, but from bacterial growth on fabric.

"HEMP Air" has demonstrated high antibacterial performance in fabric testing. It also shows reduced odor levels for common odor-causing compounds such as acetic acid and isovaleric acid. The design prioritizes comfort through the inherent properties of the material, avoiding reliance on chemical finishes or synthetic fibers.

4. Lightweight Fabric with Over 80% UV Blocking

"HEMP Air" provides UV protection suitable for daily outings and outdoor activities. Despite being made entirely of natural materials, it achieves high UV shielding without any chemical UV-blocking agents.

UV protection rates by color: Navy 87.8%, Sage Green 84.1%, Natural 81.5%, Dusty Pink 80.9%.

Ideal for city walks, travel, camping, festivals, and hiking—this T-shirt performs across various sun-intensive scenarios.

5. Natural Materials Used in Sewing Threads and Care Labels

At tennen, natural materials are used in small components such as sewing threads and care labels wherever possible, supporting material recyclability of natural fibers. The brand aims to create clothing that, after its useful life, can return to the earth.

"HEMP Air" uses natural materials (cotton) for sewing threads and care labels, prioritizing both comfort and sustainability.

Color Variants

Colors range from basic shades that highlight hemp’s natural texture to nuanced tones perfect for summer wardrobes.

Special Early-Bird Rewards Available on Makuake

To celebrate the project launch, Makuake offers limited-time discounted rewards.

Planned retail price: ¥12,100 (tax included)

• [Super Early Bird 25% OFF] Makuake price: ¥9,000

• [Early Bird 17% OFF] Makuake price: ¥10,000

Limited rewards will end once the predetermined quantities are reached.

About tennen

tennen is a Japanese apparel brand launched in 2018. Using natural fibers such as cotton, hemp, merino wool, and Japanese paper, the brand creates clothing that feels good both physically and emotionally.

The brand stands by four core concepts: "biodegradability," "innovative recycling systems," "traceability," and "Made in Japan." From fabrics to ancillary materials like sewing threads and care labels, tennen uses nature-based materials wherever possible. The brand aims to create garments that are long-lasting and ultimately return to nature. Initiatives include the "BORO" series, which transforms worn-out cotton garments into new yarn, positioning tennen as a circular fashion brand.

Contact

YS International Co., Ltd.

Contact: Hayakawa, Suzuki, Ueda

Email: [email protected]

tennen Official Website: https://tennengood.com/

YS International Corporate Site: https://www.ys-international.co.jp/

Instagram: https://www.instagram.com/tennengood/