心石工芸のものづくり

KOKOROISHI KOUGEI – ソファづくりへのこだわり –

Aging gracefully

Wouldn't it be nice to be able to use a sofa that you treasure forever?

A good sofa needs to be sturdy. This in turn is decided by the materials used in its frame and cushions. Using tried and proven materials to make a sofa is the key to creating a lasting product.

But above that the sofa needs to evoke a sense of attachment - a sense of growing fonder of it the longer it forms part of your home. This is the core that we apply when creating our sofas.

For this to be possible, the sofas need to be made with an evergreen design and materials which age gracefully.

Sofa design trends change and there are many models which will look odd ten years from now. We do not chase trends because we want to make sofas that last - our designs are meant to be appreciated no matter what the current trend is.

Our materials are also chosen to age gracefully. Vinyl leather for example, is a convenient material to use. However as it gets damaged it loses much of its charm. On the other hand, properly oiled wood may get discolored due to water stains, but those imperfections add to its story and its flavor. We only choose materials which will gain character through the years and decades of use.

Sofas which can be your companions as the years go by. We want to enrich your lives by providing sofas worthy of this.

Living contently

心豊かな暮らしとは、どんな暮らし方でしょうか? 毎日の暮らしの中にある、ちょっとした心地よさが、心豊かに暮らすために必要だと、私たちは考えています。 自宅に帰った時に、座り心地が良いソファが待っている。心地いいソファがお気に入りのリビングを飾っている。肌触りの気持ち良い素材に包まれてうとうとする。そんなちょっとした幸せを大切に思っています。

A welcoming sofa can be like a fireplace in your home - drawing both friends and family to gather around it to exchange experiences and deepen ties.

Our motivation, and the pride and enjoyment that we have in our work, is to create sofas that can do this, and become a comforting constant in your home.

The KOKOROISHI Philosophy

  • Keeping Trust

    The quality of our sofas is a fruit of the trust that we have built - with not only our customers, but with our suppliers and employees.

  • Imagination Into Reality

    We do our best to fulfill our customers' needs - including flexibly customizing our sofas' sizes, colors, textures and design. Feel free to tell us what you imagine for your ideal sofa.

  • Towards Better Sofas

    We are always listening to our customers and constantly changing to accomodate shifts in peoples' lifestyles. We are committed to continually improving our sofas through constantly experimenting with new materials and production techniques.

  • PROCESS

    PRODUCTION PROCESS

    1. Diagrams

    We start with examining our designs' intended audience, material strength, texture etc. and transforming them into product specifications and diagrams.

    2. The Frame

    The weight and spring supporting parts of our sofa frames are made of solid wood. The other parts are made instead with plywood. This gives our sofas the sturdiness they have for long-term use.

    We assemble the frame after processing the wood - ie. carving, shaving and removing corners. Our attention to detail in this process is what gives our sofas their fine finish.

    3. Placing the Springs

    We proceed by then placing the springs. The appropriate application of springs is essential to a comfortable sofa. We therefore place a combination of S-Springs, pocket coils and upholstery webbing where they will add the most comfort.

    4. Placing the Foam

    The next step is placing the urethane foam on top of the springs. This layer is not visible but is extremely important as it decides not only the shape of the sofa, but also how hard or soft it is.

    5. Cloth Cutting

    We then cut the fabrics to the shapes and sizes as indicated in our specifications. Each fabric type has a different elasticity and we pay attention to this as we shape each piece of cloth.

    6. Leather Cutting

    Each piece of leather is hand-cut. Our craftsmen take care to form the necessary shapes while avoiding unnecessary flaws of the original cow leather.

    Each of our craftsmen is well equipped to both judge and cut the best parts of the hide to use.

    7. Stitching

    The process of joining the cloth and leather together to create the exterior of the sofa. As we sew the two together, we add in small details such as stitches that add depth to the overall finish of the product.

    It takes skill to sew flexible materials straight. We have the experience to handle this and the other work that goes into the complexity in the exteriors of our sofas.

    8. The Finish

    Placing the exterior on the prepared frame.

    The materials used in the exterior can differ in terms of elasticity and how rigid they are, even between individual pieces. Our craftsmen are aware of these variations and work around them to make a consistent finish.

    This step involves hammering materials to shape them, sewing the corners etc. - all the hands of our experienced craftsmen with their painstaking attention in making the perfect sofa for you.

  • CRAFTSMEN

    CRAFTSMEN
    • TETSUMA MIZUKAWA
      TETSUMA MIZUKAWA
      Carpentry

      Experience: 7 years.
      The wood frames of sofas may look simple - but they actually are a complex combination of parts called "stalks", "joists" etc. Tetsuma is in-charge of processing, cutting and assembling the wood. On the factory floor he confidently handles the large wooden fames and describes his work as a daily process of improving himself.

    • YUTO FUJIWARA
      YUTO FUJIWARA
      Frame Attachments

      職人歴:5年 肘掛けの丸みを帯びた角や、背クッションの緩やかな曲線。ただ座るためだけのソファから、より心地のよいソファにするために、ウレタンを摘んだり、曲げたり、巻いたり、工夫を凝らしています。新しいモデルを開発する時には、ウレタンの専門家として「どうウレタンを貼るべきか」を提案することもあります。時間のかかりすぎる貼り方や、難易度の高い貼り方を避けることで、工場全体の生産性の高さや品質の高さを維持しています。

    • TAKAYUKI OKADA
      TAKAYUKI OKADA
      Process Management

      職人歴:16年 工場の生産量を決める工程管理や資材の発注を行っている岡田くん。工場の要となる仕事です。下張り、上張りの経験を積んでいます。「気をつけていることは、できないって言わないこと」と。トラブルを解決する力と判断力で今日も業務を一つ一つ着実に進めています。

    • 大垣 誠
      MAKOTO OGAKI
      Exterior

      職人歴:30年 国家資格、椅子張り技能士1級を持つ大垣さん。「昨日より少しでも綺麗に仕上げること。日々高みを目指したいですね。」と。ソファの最後の工程である張り。想いを込めて、一つ一つ丁寧に仕上げていく様子は、淡々としているようで、高い技術を持っているからこそできることです。

    • MIZUE YAMANE
      姜 春花
      Leather Cutting

      職人歴:14年 革は職人の手で一つ一つ裁断しています。上質な革ほど牛のナチュラルマークがあり、どのように入れるか判断するのも職人の匙加減です。「牛のおしりと頭の部分ではシボが違いますが、仕上がった時、同じようにシボが出るよう工夫しています。」と姜さんはいいます。天然のものに向き合い、熟練されたきれいな裁断のラインと職人の革に対する工夫がソファの完成度を高めてくれます。(ナチュラルマーク:牛の生前の切り傷や虫刺され、シワ、血管の痕のこと。)

    • KAORI MATSUOKA
      安田 理加
      Fabric Cutting

      職人歴:5年 「裁断の仕事なら一通りこなしてきました。好きな生地や革に囲まれて仕事ができることが幸せです。」そう答える安田さんはテキパキと機械を使って布を切り、生地がよれていないか、微調整をしていきます。布によって伸びやすい方向があるのでチェックをしつつ、布に傷がないか確認しています。多いときで1日20台分の布を裁断することもあるそう。なんとなく座っている生地でも素早く厳しい目でチェックしてくれているからこそきれいな柄や生地でソファは仕上がるのです。

    • TATSUYA UCHIDA
      酒井 穣司
      Patterns

      職人歴:1年 「ミリ単位の誤差が、仕上がりに影響してくることを木工の現場から学んだので、パターンを出すときも意識しています。」と酒井さんは話します。パタンナーは完成するソファに合わせて、型出しをします。ソファの試作や張替え、生地がどれくらい必要かを出すこともパタンナーの仕事です。その中でも張替えは難しい作業です。現物の生地と同じように型を作っていても、生地の劣化や伸び、縮みで新品の時と同じような状態で仕上がらないこともあります。何度か木枠とウレタンを張ったものに布をかぶせてサイズをあわせて微調整をします。木工、縫製、ウレタン、張り、ほぼすべての部署の知識を必要とされます。これからの活躍に期待です。

    • KAORI KAWAMOTO
      永見 淑恵
      Sewing

      職人歴:12年目 縫製現場の工程管理も行う永見さん。資材発注の指示や納期に間に合うよう日程調整をします。「完成品を見る機会が少ないので、お客様の納品事例の写真を見たとき、とても励みになります。」と嬉しそうです。永見さんはいつも縫い目がまっすぐになるよう気をつけて縫っています。当たり前のように思えるかもしれませんが、ソファの角の部分は生地が重なり厚みが変わるので難易度が増したり、革の生地は縫い間違いができないのでかなり気を使います。また、縫い方が中途半端だとソファを張っている際に糸が浮いてきてしまいます。端切れで何度も試し縫いをし、針の細さを変えて糸調子をあわせます。そのような細かい調整を行なって初めて縫うことができるのです。

    • KEIKO KAMBARA
      KEIKO KAMBARA
      Admin

      入社:8年目 お客さんとの電話対応窓口になっている神原さん。「仕事がたくさんある時、スムーズに終わると達成感がありますね。あと、お客さんから感謝の気持ちを言われた時。」どんな電話でも丁寧に対応してくれているからこそ、顔が見えなくても気持ちが伝わると思います。定年まで元気で頑張っていただきたいです。

  • PARTNERS

    PARTNERS
    • Leather Tanning
      SUMIDA SANGYO CO. LTD.

      The company behind the smooth and flexible oil leather in our sofas.
      Leather is a complex problem - one can only see the leather quality after removing the hide's fur. Only 20% of hides qualify as "quality leather" at this stage. In addition, out of these, only a minority can be used for oil leather or tanning. The leathers that we use are only around 2-3 pieces per 100 - with marks that make each piece unique, and strong enough such that only light processing is needed.

    • Springs
      KYUSHU SEAT SPRING KOGYO CO. LTD

      Springs decide how a sofa feels when someone sits on it. This is also why we pay so much attention to ensure that the springs we use are at just the correct rigidity.
      The springs we receive are made in Japan, with a high carbon content and with a consistent composition. Our supplier's production involves smelting in a specialized furnace that keeps a constant temperature and a gradual, natural cooling process. Quality springs for quality sofas.

    • Urethane Processing
      AISHIN INDUSTRIAL CO. LTD.

      There are actually more than 100 types of Urethane foam. For example, Chip Urethane is one of our preferred materials given its cushioning and low ecological impact.
      Each of our sofas requires a different configuration. Therefore, these types of urethane need to be correctly selected, layered and shaped to make the foam in our sofas. The foams that we select have a high elasticity ratio and while providing a great cushion they are also made to last.

    • Urethane Synthesis
      INOAC CORPORATION

      INOAC holds world-class technology and 40% of the Japan market for synthesizing. Different synthesizing conditions can lead to urethane varieties which differ in elasticity, durability and flexibility. Urethane is formed through mixing polyol and isocyanate - the mixture will bubble into urethane foam. However, careful handling is needed in taking to account the ambient temperature and humidity of the conditions and in ensuring that the urethane produced is uniform.

    • Fabrics
      SINCOL CO. LTD.

      SINCOL handles deftly all aspects of fabric work for us, including spinning, dying, weaving and the final processing.
      Fabrics too are a difficult subject. Natural materials like cotton and wool are soft and because they absorb moisture. This is what makes them cool in summer and warm in winter. Synthetic fabrics do not have this advantage but are stronger. We mix different fabrics, drawing from the strength of each to bring you the best combination and the best sofas possible.

    • Tool Maintenance
      ARATANI

      Aratani performs maintenance on the indispensable tools of our trade. The tools that require the most maintenance are our tackers - which are necessary in the carpentry, and setting both the interiors and exteriors of a sofa. Tackers use pneumatic pressure to hammer nails and we need to constantly maintain them to ensure that pressure is adequate while not being too strong. Our tools are like our hands and we constantly maintain them to ensure that we keep the precision in our work.

    • Wood
      KONDO MOKUZAI CO. LTD.

      At the beginning, Kondo Mokuzai dealt with the wood for geta (traditional Japanese sandals) and heels but now now deal more with furniture wood.
      We use Japanese beech (Fagus Crenata) wood provided from them which is a proven material for furniture used from long ago. The wood they provide is PEFC certified wood from Pollmeier, a German company, committed to sustainable forestry through growing their own wood trees. Sustainable wood for a durable sofa frame - that is what we use.

    • Carpentry
      KOEISANGYO CO. LTD.

      KOEISANGYO produces the visible wood parts of our sofas - such as the "elbows" and legs. They carefully make each piece from North American walnut wood through applying their Rocking Cutting technique. Once the wood arrives at their factory, they place it in a dryer to make it better fit the Japanese climate. This also evens out possible curves in the wood. They then saw and combine the wood pieces. Their accuracy is to the milimeter, which is why each piece fits exactly which each other.

    • Cushioning
      KASHIMOTO KENMEN CO. LTD.

      Kashimoto Kenmen commits to making comfortable cushioning which best brings out the quality of the cotton and feathers they use. The feathering used are duck small feathers - which have very small spines. Kashimoto Kenmen applies their skills to make cushioning where the feathers do not protrude at all, and which is resistant to deforming. Due to this, people sitting on the sofas feel only of the softness and comfort of the feathers use.

    • Cardboard
      EFCO ALRIGHT CO. LTD.

      Our sofas are sent from Hiroshima to the whole of Japan. EFCO Alright provides the protective cardboard it gets sent in. The cardboard we use is a double layered cardboard with both a 3mm and 5mm layer. The glue is also applied at a fixed temperature to ensure maximum strength. All this goes into ensuring that our sofas are delivered in perfect shape to our beloved customers.

ソファ屋社長、心石のnote

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