Kiso Koma-jirushi

Maruya Seisakusho is based at 11002-3 Tsukechi-cho, Nakatsugawa, Gifu. The company focuses on bent-wood kitchen tools used every day, with professional steamers at the center. Their main sales channel is business-to-business, working with wholesalers and distributors for professional use. Phone and fax support is available, and their stated contact hours are 10:00-17:00.

The history begins in September 1953, when the founder's great-grandfather, Yoneichi Yasue, started making hand-split hoops. In September 1970, the first generation, Kenichi Yasue, began producing Chinese steamers, Japanese steamers, and uragoshi strainers. After training in Tokyo to learn seiro-making, he returned to Tsukechi and started production. In February 1970, the workshop also built the base for machine-assisted production using sawn hinoki boards. A new factory was established in 1994. In 2007, the company name was changed to Maruya Seisakusho Co., Ltd., and since 2010 the CEO has been the third-generation representative, Kensuke Yasue.

A seiro goes through close to 30 steps. Maruya uses Japanese hinoki — Tono hinoki and Kiso hinoki — and bends the boards in-house. By combining long-held know-how with their own forming equipment, they aim to minimize gaps and keep quality stable. They also make use of side boards left after cutting pillar timber, a practical way to avoid waste. In their FAQ, they note that wood will age (color changes and small cracks can happen) and emphasize that, as a toolmaker, strength comes first.

The lineup covers standard Chinese steamers (15cm and 21-30cm), plus custom sizes with movable or fixed handles and an inro-style type. For larger custom pieces, the bottom board can be woven from bamboo and reinforced with stainless bars. They also make an 18cm ohitsu (for about 3 go of rice) with carefully aligned cherry-bark stitching and no metal fittings, which allows microwave use. Other bent-wood items include Japanese steamers, flour sifters, buckets, and uragoshi strainers using horsehair mesh. Custom orders are handled when craftsmen availability allows.

In-house craft, steady fit

From bending to final fit, everything stays in-house. A seiro is said to take close to 30 steps, and Maruya combines traditional know-how with their own forming equipment. The result aims for fewer gaps and consistent stability in daily use.

Japanese hinoki, used wisely

They work with Japanese hinoki such as Tono and Kiso hinoki. One notable detail is using "side boards" left after cutting pillar timber — making the most of good wood rather than wasting it. Cleaner grain is selected for a better feel and finish.

Woven bamboo lid, smart sizes

Their lids are woven from bamboo, designed to let steam escape gently so condensation is less likely to drip onto food. Sizes include 21-30cm plus a compact 15cm. From 24cm upward, the body becomes 1.5cm taller with an extra wrap and thicker boards for added strength.

Toolmaker mindset, strength first

They describe themselves as toolmakers, not makers of decorative crafts — and strength is the priority. Large custom pieces can be reinforced with stainless bars, and bonding is kept to a minimum while using an adhesive that complies with Japan's Food Sanitation Act. It's a pragmatic, kitchen-first approach.