Kiryu is a small city in Gunma Prefecture, about two hours north of Tokyo by train. It's been a silk-weaving centre since at least the eighth century, when the region's climate and access to mulberry trees made it a natural home for sericulture. At its peak in the Meiji era, Kiryu was producing silk for export across Europe and North America. Most of that industry is gone now. A handful of family mills remain.

The history of Kiryu weaving

Kiryu's weaving tradition is documented in records from the Nara period (710-794 AD). The city became a major silk centre during the Edo period, when it developed a reputation for nishiki-ori, a complex brocade weave used in formal kimono. During the Meiji industrialisation, Kiryu adopted power looms while maintaining the design traditions of the hand-weaving period. By the early twentieth century, it was one of the largest textile-producing cities in Japan.

What habotai silk is and why it works for lingerie

Habotai (羽二重) is a plain-weave silk with a smooth, even surface and a soft drape. The name translates roughly as 'feather two layers'. It was historically used as a lining fabric in kimono, which means it was designed to sit close to the skin, move with the body, and not create friction. These properties make it ideal for a slip or a nightgown. At 12 momme (the weight we use), it's light enough to drape on the bias without clinging.

The Hayashi family mill

The mill we work with has been run by the Hayashi family since the 1960s. They operate three looms, produce a small range of habotai and habutae weights, and sell almost exclusively to domestic buyers. They don't have a website. Yuki found them through a fabric buyer at a Kyoto kimono maker in 2019 and has been ordering from them since 2020. The relationship is straightforward: we visit once a year, select the run we want, and they produce it to our colour specification.

What changes from year to year

The thread count and weave structure stay consistent, but the exact drape of the fabric varies slightly with the season and the silk harvest. The April 2026 visit found a marginally heavier thread count on the 12-momme weight, which produces a slightly stiffer hand off the bolt but a better drape after the first wash. These are small differences, but they affect how the finished slip behaves on the body, and they're worth noting.

Kiryu silk is not a marketing story. It's a specific material from a specific place, made by a specific family, and it behaves differently from silk sourced elsewhere. That specificity is why we use it.