The Techniques of Nedo Fumi and Sedge Craftsmanship at

Nedofumi and Sedge Craft Techniques of Kuni-Iriyama: A Living Heritage of Mountain Life

Deep in the mountainous Iriyama district of Nakanojo Town, Gunma Prefecture, a remarkable folk craft tradition has been handed down through generations. Known as "Nedofumi," this technique involves soaking sedge grass (suge) in naturally flowing alkaline hot spring water to soften its fibers, which are then woven into everyday tools and footwear. Selected in 2016 as a nationally recognized intangible folk cultural property requiring documentation and preservation measures, the Nedofumi and Sedge Craft Techniques of Kuni-Iriyama offer a fascinating window into how Japan's mountain communities ingeniously harnessed the gifts of nature — volcanic hot springs and wild grasses — to sustain their daily lives.

Historical Background

The Iriyama district, part of the former Kuni Village (六合村, merged into Nakanojo Town in 2010), sits in the remote highlands of the Agatsuma region in northwestern Gunma Prefecture. For centuries, the residents of this area lived in relative isolation, surrounded by mountains and blessed with abundant natural hot springs, including the famous Shirizaki Onsen, where hot water bubbles directly from the riverbed.

In this harsh yet resource-rich environment, villagers developed a unique method of processing sedge and other wild plants. Each autumn, the entire community would harvest sedge grass from the surrounding meadows. The freshly cut stalks were then submerged in pools of naturally heated alkaline spring water — a process called "Nedofumi" (literally "soaking at the root"). The alkaline minerals in the water gently broke down the tough plant fibers over a period of ten days to two weeks, making them supple and workable without damaging their inherent strength. After soaking, the sedge was sun-dried and stored for the long winter months, when families would gather to weave mats (mushiro), sandals (konkon-zōri), ropes, and other essential household items.

Why It Was Designated as a Cultural Property

The Nedofumi and Sedge Craft Techniques of Kuni-Iriyama were selected on March 2, 2016 as an Intangible Folk Cultural Property Requiring Documentation Measures (記録作成等の措置を講ずべき無形の民俗文化財). This designation reflects the technique's exceptional value on several fronts.

First, Nedofumi represents a rare example of a material preparation technique that directly utilizes a natural geothermal resource. While hot springs are widely used across Japan for bathing and healing, using volcanic spring water as an industrial processing agent for plant fibers is highly unusual and speaks to the ingenuity of mountain communities. Second, the entire production chain — from communal harvesting and spring-water soaking to hand-weaving — constitutes an integrated folk technology system that illuminates everyday life in Japan's mountainous interior. Third, as rural depopulation threatens to extinguish these skills, official recognition helps ensure that the knowledge is recorded and transmitted to future generations.

The Nedofumi Process and Sedge Crafts

The Nedofumi process begins at a communal hot spring site along the riverbank. Villagers dig into the riverbed, line the depression with stones to create a pool, and allow naturally heated alkaline water to fill it. Bundles of harvested sedge are then submerged and weighted down. Over the next ten to fourteen days, the mineral-rich water works its magic, softening the rigid fibers to just the right degree of flexibility. The sedge is then removed and dried thoroughly in the sun.

The resulting material has a beautiful luster, remarkable durability, and a pleasant suppleness. From this treated sedge, artisans produce a variety of items, most notably "Konkon-zōri" — traditional straw sandals woven with sedge cord cores that are prized for their sturdiness and breathability — and "Mushiro," woven mats used in farming and daily life. Other products include ropes, baskets, and various household implements. The Nehiroba community's Konkon-zōri, made with sedge cord as the core and a distinctive weaving technique, are especially celebrated for their quality.

Visitor Information: Nedofumi no Sato

The primary place to experience this tradition firsthand is "Nedofumi no Sato" (ねどふみの里), a heritage transmission facility located in Iriyama, Nakanojo Town. Housed in a renovated traditional mountain farmhouse, the facility serves as the base of operations for the Nedofumi no Sato Preservation Society.

Visitors can observe artisans at work, watch demonstrations of sedge weaving, and — with advance reservation — participate in hands-on workshops. A full-day Konkon-zōri weaving experience is available for 5,000 yen, while a one-hour sedge mat weaving session costs 1,000 yen. The facility also sells finished Konkon-zōri, wild grape vine baskets, and other handmade crafts, as well as local produce such as dried mushrooms, beans, and grains. A welcoming cup of coffee is offered at the entrance for just 100 yen.

Nedofumi no Sato is open from 9:00 AM to 4:00 PM, though it is closed during the severe winter months. Reservations can be made by phone at 0279-95-5324. The facility is located along the road toward Lake Nozori, in the Nehiroba area of the Iriyama district.

Surrounding Attractions

The Kuni (六合) area of Nakanojo Town is a treasure trove of natural and cultural wonders, making it well worth extending your visit beyond Nedofumi no Sato.

• Shirizaki Onsen (尻焼温泉) — A legendary open-air hot spring where the entire riverbed becomes a natural bath. The same geothermal waters used in the Nedofumi process can be enjoyed here for bathing.
• Akaiwa Preservation District (赤岩重要伝統的建造物群保存地区) — A nationally designated historic village with beautifully preserved Edo- and Meiji-era sericulture farmhouses, and a component of the Japan Heritage "Kakaa Tenka" silk story.
• Chatsubomigoke Park (チャツボミゴケ公園) — Home to Japan's largest colony of Chatsubomigoke moss, which thrives in highly acidic volcanic spring water. Designated a National Natural Monument.
• Lake Nozori (野反湖) — A pristine alpine lake at 1,513 meters elevation, surrounded by wildflower meadows and popular for hiking and camping.
• Yodachi Yataki (世立八滝) — A series of eight waterfalls in a dramatic gorge, accessible via hiking trails.
• Former Ōshi Station (旧太子駅) — A restored wartime-era railway station that once served the local iron mining industry, now a historical site open to visitors.