Since 2022, Musashi Hamono and Tsushima Island have partnered to assist in cleaning the ocean coastlines and create the Ocean Knife, a sustainable kitchen knife made from recycled materials collected during cleanup efforts.
Tsushima is a remote island between Japan and Korea, shaped by its strategic location. Its traditions reflect centuries of maritime heritage and craftsmanship.
The island has a deep connection with nature, like the use of Shiratake mountain as a navigational landmark. The shrines offers a place for the relationship between people, nature, and the deities.
Tsushima's nature is characterized by dense primeval forests covering about 90% of the island, which is home to a unique ecosystem.
The Tsushima leopard cat is a distinct subspecies found nowhere else in the world but on the island of Tsushima.
Today, Tsushima is the island with the most marine plastic debris in Japan, where plastic pollution is a local problem with global impact, threatening both nature and the community.
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Local Change – Global Impact
The waves that reach Tsushima’s shores carry more than beauty— they bring the unresolved weight of our global crisis. In 2023, 881 kg of plastic was collected here, yet the flow has not stopped. Ocean currents ensure this waste does not stay local—it spreads across ecosystems, enters marine biology, and ultimately the food we eat. What happens on this small island is a warning to us all: if left unresolved, local struggles will become a worldwide disaster. By choosing to support our cause, you stand with a movement that refuses to let the problem drift into the future.
Chokin is an ancient Japanese engraving technique that once adorned samurai swords, armor, and ceremonial treasures. Later, it adapted to modern needs, and today there are only few known craftsmen that still produce this craft.
Transforming ocean plastic into the MUSASHI Ocean Knife
From Ocean Waste to Safe Craft
Our handles begin as scattered ocean plastic chips—each piece carrying a different melting point, a unique history. Over two years of development, we faced the challenge of shaping these fragments into a solid, functional handle. To ensure complete food safety, we enveloped the surface with a thin protective film.
Shaped by Feedback, Refined by Time
The first prototypes were bulky, rough in form. Through continuous feedback from our customers, we refined the design—streamlined, balanced, and reshaped into the traditional octagonal handle. Later generations even integrated NFC chips, bridging tradition with technology.
Knives That Carry the Ocean’s Story
Today, the Tsushima Ocean Knives evolve with the seasons—each new color reflecting the ever-changing sea. Available across all MUSASHI stores, these handles resonate deeply with our customers. They are not just tools, but stories of the ocean, of resilience, and of craftsmanship.
The Tsushima ocean knife may be a small approach, but we believe that if we continue it for a long time and get more people interested, surely the next generation and the generation after that will be able to continue to live on this beautiful planet.
Sdgs partners
We became an SDG Tsushima partner in January 2023 and were awarded the certificate for sustainable partners. We opened our store there in July 2022 as part of the local government’s business development strategy.
Located in Tsushima City, Nagasaki Prefecture, the store supports the local economy and promotes sustainability. Due to the island’s location, our store welcomes many visitors from neighboring Asian countries and serves as a center for raising awareness about the environmental damage affecting the island.
The Tsushima Ocean Knife bears a handle sculpted from reclaimed marine plastic, rescued from Tsushima Island’s shores. Beyond exceptional sharpness, an embedded NFC chip carries its story. A simple tap reveals the narrative of transformation. Each season, Musashi Japan introduces a new line of Ocean Knives, continuing our commitment to sustainability.
