The Art of Making ‘Japan Blue’; Founded in 1914, Nogawa Senshoku Kogyo Continues Making Dye for Popular Color Using Traditional Techniques

By Hidenori Sato / Yomiuri Shimbun Staff Writer

16:29 JST, December 15, 2025

HANYU, Saitama — Thirteen jars of indigo dye are lined up beneath the factory floor. Each jar contains dye that has undergone a different fermentation period and varies in dyeing strength.

An artisan steadily and quietly repeats the task of dipping bundles of thread into the jars at his feet and pulling them back up. “I’m proceeding with the work while carefully examining the dyeing degree and color tone to ensure the indigo permeates every corner,” he said.

The area of Hanyu in Saitama Prefecture is said to have been renowned for indigo dyeing since the Edo period (1603-1867), producing work clothes for farmers. In 2008, the dyeing method in the area was trademarked as “Bushu Sho Aizome,” or Bushu area’s true indigo dyeing. Founded in 1914, Nogawa Senshoku Kogyo continues to use these traditional techniques.

The dye is made from sukumo (naturally fermented indigo leaves), fusuma (wheat husks) and lime, and does not contain any chemical dyes. When the bundles of dyed thread are lifted out, the pigment reacts with the oxygen in the air and turns indigo blue. The simple, deep hues created by the varying shades of indigo are called “Japan Blue” and are popular overseas.

Another notable aspect of the method is the “pre-dyeing” process, in which the threads are dyed before weaving, rather than afterward. “The dye coating increases the threads’ strength, and hand-dyeing creates a unique striped pattern on the fabric called Aojima (blue stripes),” said Yuki Nogawa, 35, managing director of the firm, explaining the appeal of the dyeing method.

A kendo uniform called Bushu ichi, which is made with fabric that offers both suppleness and strength, is the company’s highly regarded original brand. When sales of kendo uniforms plummeted in 2020 due to the coronavirus pandemic, the firm seized the opportunity to diversify its product line. It developed indigo-dyed masks, slippers and other items, overcoming the crisis. The firm now offers hundreds of products, including bedding, dresses and stoles.

Hundreds of indigo dyeing workshops are said to have once operated in the area around Hanyu. Today, however, the city only has three. Nogawa reaffirms his resolve to preserve the local industry.

“While preserving traditional techniques, we aim to continue developing products closely tied to daily life,” he said.

Nogawa Senshoku Kogyo

Address: 878 Sukage, Hanyu, Saitama Prefecture. The company-owned shop, which sells indigo-dyed products, is in 471-4 Sukage, Hanyu.

Access: The shop is five minutes by car from Hanyu Station on the Tobu Isesaki Line or a 25-minute walk from Minami-Hanyu Station on the same line.

Hours:The shop is open from 10:30 a.m. to 6 p.m. from Friday to Sunday. It also has an online store.