Carrying the wish of 80 postwar years 1,000 years into the future. From Iga, with an eternal wish for peace.
Executive Summary
Eighty years since the war. Turning the shape that pierced for justice into the shape that shares peace. A specialty product that only Iga can create, delivering that story 1,000 years into the future.
| Item | Detail |
|---|---|
| Product name | IGA NINJA SOAP |
| Shape | Shuriken-shaped MP soap (transparent base) |
| Ingredients | Iga Ninja Banana pesticide-free peel extract × matcha |
| Concept | From piercing for justice → to sharing peace. Turn 80 sideways and it becomes ∞ |
| Production partner | NPO Iga no Tomo (agri-welfare & disability employment) |
| Matcha sourcing | Michi-no-Eki Ocha no Kyoto Minamiyamashiro (ranked #1 in Japan) |
| Recording & communication | TokiStorage (preserving prayers for eternity with a 1,000-year perspective) |
Why now—The 80th anniversary since the war, a milestone everyone shares. Rising inbound tourism. Growing social interest in agri-welfare partnerships and regional co-creation. Everything converges at this moment.
Why Iga—Because the birthplace of ninja culture is speaking, this becomes authentic succession, not cosplay. It would not work from Koka or anywhere else. Iga's history, geography, and the legacy of Basho guarantee the concept's authenticity.
Why TokiStorage—Soap dissolves and disappears. But prayers do not. If Pearl Soap preserves "personal memories," Shuriken Soap preserves "humanity's prayers." The only partner that delivers records to everyone.
1. History & Origins
Birth and Historical Context
Shuriken developed as practical weapons from the late Muromachi period through the Sengoku era (15th–16th century). Primary users were ninja (shinobi), samurai, and certain mercenary groups. Rather than a primary weapon like a sword or spear, shuriken were positioned as auxiliary and disruption tools. The word "shuriken" derives from "a blade hidden in the palm of the hand."
The Iga Connection
Iga Province (present-day Iga City and Nabari City, Mie Prefecture) is the birthplace of Iga-ryu ninjutsu. During the Sengoku period, Iga ninja served various feudal lords in intelligence, assassination, and disruption missions. Though devastated by Oda Nobunaga in the Tensho Iga War of 1581, their techniques and culture were passed down. Today, the Iga-ryu Ninja Museum continues to offer shuriken-throwing experiences as a tourism attraction.
From the Edo Period Onward
With the arrival of peace, practical use declined and shuriken transformed into tools of martial training and discipline. Various schools developed distinctive shapes and throwing methods, systematizing the practice as "shurikenjutsu." After the Meiji Restoration, it temporarily declined amid the modernization of martial arts, but shuriken culture endures to this day.
2. Types & Shapes
Bo-shuriken (Stick Shuriken)
Elongated, nail-shaped shuriken made of iron or steel. They deliver high penetrating power through straight-line throwing and are easy to conceal in clothing. Used in schools such as Toda-ryu and Negishi-ryu.
Kuruma-ken & Multi-Pointed Shuriken
The shape widely recognized today as the "ninja star."
| Shape | Characteristics |
|---|---|
| Four-pointed (4 blades) | The most classic design. Well-balanced |
| Six-pointed (6 blades) | High stability, suitable for beginners |
| Eight-pointed (8 blades) | Excellent flight stability |
| Manji (swastika-shaped) | Asymmetric form with a distinctive flight pattern |
| Triangular | Acute angles for high penetrating power |
Other Shapes
- Cross-shaped: The image most common in films and games
- Diamond-shaped: Simple and easy to produce
- Flower-shaped (cherry blossom, plum): Widely used in modern decorative souvenirs
3. Uses & Tactics
Battlefield Applications
- Disruption & diversion: Halt or distract the enemy
- Escape aid: Throw at pursuers to buy time
- Blinding: Aimed at the face to impair vision
- Poison application: Coated blades make even small wounds lethal
Non-lethal Uses
- Sound decoys: Metallic sounds or ground impacts to misdirect enemies
- Multi-purpose tool: Cutting vines or cloth, picking locks, and other utility tasks
Modern Uses
- Martial arts & competition: Shurikenjutsu demonstrations and tournaments
- Tourism experiences: Activities at ninja-themed parks
- Collecting: Historical craftsmanship as collectibles
- Entertainment: Iconic items in films, anime, and games
4. Crafting (Traditional Methods)
Materials
Traditionally made from iron or carbon steel. Thickness ranges from approximately 3–6mm depending on the intended use.
Manufacturing Process
- Template: Drawing the shape onto a metal plate or applying a pattern
- Cutting: Carving out with chisels or grinders
- Grinding: Sharpening the blades to a fine edge
- Heat treatment: Quenching (hardening) followed by tempering (adding toughness)
- Polishing: Smoothing the surface
- Center hole: Drilled for rotational stability
Some blacksmith workshops in Iga City offer hands-on programs, with simplified versions where participants cut thin metal sheets with grinders also proving popular.
5. Throwing Techniques
| Technique | Characteristics |
|---|---|
| Seite-uchi (overhand) | The basic form, using wrist snap to generate spin |
| Gyakute-uchi (underhand) | Reversed wrist motion for a curving trajectory |
| Suihei-uchi (horizontal) | Thrown flat to cover a wide area |
| Suichoku-uchi (vertical) | Vertical spin, designed to stick into the ground |
Effective range is approximately 5–10 meters (practically 3–7 meters in combat). Modern competitions focus on target accuracy.
6. Culture & Trends
Pop Culture Penetration
The global success of the anime NARUTO cemented the "ninja = shuriken" image worldwide. Ninja and shuriken appear frequently in games and Hollywood films. On social media, shuriken-shaped goods, foods, and crafts regularly go viral.
Experiential Tourism Trends
Demand for ninja experiences in Iga and Koka is particularly high among international visitors (inbound tourism). The market for "try it and take it home" souvenirs is growing, with product design increasingly shaped by visual appeal and social media shareability.
Shuriken-Shaped Goods Today
- Shuriken-shaped cookies and chocolates
- Shuriken-shaped keychains and accessories
- Shuriken-shaped pizza cutters and kitchen tools
- Shuriken-shaped soap (a few exist, but full-scale specialty product development remains untapped)
7. Core Concept: From Warfare to Peace
"Turning Shuriken into Soap"
The shuriken was wielded to pierce through in pursuit of justice. Soap is shared to cleanse in pursuit of peace.
The aspiration is the same. Only the means have changed with time.
The ninja did not fight out of malice.
They risked their lives to protect their villages, for the sake of justice.
We do not deny their spirit—we inherit it in a new form.
This is not a critique of weapons. It is the succession of a conviction.
Three Layers of Meaning
| Layer | Content |
|---|---|
| Succession of conviction | From a shape that pierced for justice to a shape that shares peace. The spirit remains |
| Temporal context | 80 years since the war—not "the war ended" but "the conviction changed form" over 80 years |
| Numeric transformation | Turn 80 on its side and it becomes ∞—a wish for eternal peace |
No explanation needed. Those who hold it discover the meaning on their own. Discovery becomes emotion, and emotion becomes memory. That is the design.
Eighty years since the war. Turn that number on its side, and it becomes ∞.
The shape that once pierced for justice now shares peace.
From Iga, with an eternal wish.
Reference: Swords into Plowshares
The universal peace metaphor from the Book of Isaiah: "beat their swords into plowshares." But what this soap speaks of is not denial—it is succession: carrying forward the conviction of those who once bore blades, in a form fit for today.
Why It Must Be Iga
If someone elsewhere makes shuriken soap, it becomes cosplay. When Iga makes it, it becomes authentic succession.
| Reason | Detail |
|---|---|
| Historical stakes | Iga was actually destroyed in the Tensho Iga War. When the descendants of that land say "we wish for peace," the weight is something no other place can replicate |
| Context of justice | Iga ninja were defenders, not invaders. The phrase "pierced for justice" rings true. Even Koka carries a different context |
| Geographic isolation | A basin surrounded by mountains. The very terrain that was defended against outside invasion forms the backdrop of the concept |
| Matsuo Basho | Born in Iga to a samurai family, Basho pursued beauty through haiku. A predecessor who lived by transforming conviction into a new form already exists in this land |
"Only Iga can do this" is not a matter of market differentiation. It is a matter of conceptual authenticity.
Storyline
Ninja carried shuriken to fight. But what they truly wanted to protect was their families, their villages, their peaceful daily lives. Transforming that shape into soap may be a way of receiving their true wish in the present day.
8. Implications for Development
Shape Design Hints
| Shape | Appeal as a Specialty Product |
|---|---|
| Four-pointed shuriken | Highest recognition. Universal appeal |
| Cherry blossom / plum blossom variation | Combines Japanese aesthetics with charm |
| Iga-original design | Incorporating Iga-ryu family crests and motifs |
Materials & Fragrance Direction
- Pine & Japanese cypress (hinoki): Evoking the ninja's mountain training
- Ink & sandalwood (byakudan): Japanese spiritual aesthetics
- Iga-yaki clay: Regional character (as a bath additive element)
- Tea: Iga tea (collaboration with regional agriculture)
Packaging & Story
- "Gripped and thrown by hand" → "Cleansing the hands"—a conceptual pivot
- Scroll-shaped or wooden-box packaging for a sense of occasion
- English and multilingual support to capture inbound tourism demand
Partnership with NPO "Iga no Tomo" Banana Farm
An NPO that operates through agri-welfare partnership, centered on disability employment support and banana cultivation. The variety grown is Gros Michel, a Taiwanese banana cultivated using the freeze-thaw awakening method (−60°C ultra-low temperature stress to awaken environmental adaptability) in the mountains of Iga, completely pesticide-free. First shipped as "Iga Ninja Banana" on Ninja Day (February 22).
Bananas that endure extreme stress × Ninja who endured extreme training—these two share the same structure. Add the agri-welfare axis, and the shuriken soap story connects to contemporary social issues.
The shape of the ninja who fought for justice now becomes a soap that shares peace, made with bananas grown by people with disabilities.
"Succession of conviction" expands from past to present, and into society. Banana oil and peel extract are practical soap ingredients, and the name "Iga Ninja Banana" itself becomes the product story. Collaboration with the NPO adds social impact and empathy, deepening the motivation to purchase.
Co-development with Michi-no-Eki Minamiyamashiro
Ranked #1 in the 2024 national "Strongest Michi-no-Eki" ranking. Located on the national highway from Kyoto to Iga—the gateway to Iga. Serves fresh handmade matcha sweets daily and has established itself as a nationally recognized matcha brand. A roadside station built by the village of Minamiyamashiro (population approximately 2,800) by turning its designation as a "community at risk of extinction" into an advantage.
| Minamiyamashiro | Iga | |
|---|---|---|
| Background | Community at risk of extinction; Kyoto's only village | Devastated in the Tensho Iga War |
| Strategy | Protecting the village with authentic tea | Inheriting conviction in new forms |
| Common ground | Small communities surviving through the power of authenticity | |
The concept shares the same roots as the shuriken soap project. That is why the collaboration has inevitability. Using Minamiyamashiro's matcha as a soap ingredient and selling shuriken soap at the roadside station creates a cross-regional story: "a soap of peace connecting Kyoto and Iga." Partnering with the #1 roadside station in Japan amplifies reach instantly.
9. Materials & Manufacturing Design
Basic Composition
| Element | Detail |
|---|---|
| Base | Transparent MP soap base (melt & pour) |
| Extract | Iga Ninja Banana pesticide-free peel decoction extract |
| Color & fragrance | Matcha (from Michi-no-Eki Minamiyamashiro) |
| Shape | Shuriken mold (IGA NINJA SOAP) |
Why This Combination
Transparent base × banana peel extract (amber) × matcha (green) naturally produces deep moss green, olive, and fallen-leaf tones. The color of ninja camouflage, blending into the mountains. Without intention, the ingredients gravitate toward the aesthetics of the ninja.
Transparent soap transmits light. Hold it up and the color glows from within. Before use it looks like a weapon; in your hands it dissolves into lather—the process itself becomes the experience of the concept.
Philosophy of the Recipe
What shows: the color, fragrance, and shape of matcha. What remains hidden: the banana peel compounds, the story of agri-welfare partnership, the prayer of 80 postwar years.
This is the ninja itself. It does not announce its presence. But it is undeniably there.
It aligns with TokiStorage's philosophy as well—just as a QR code harbors invisible information, banana peel harbors invisible compounds. Within the form, an invisible prayer resides.
Recipe (Final Version)
[Preparation] Performed by Iga no Tomo
- Tear the peels by hand
- Dry-roast in a frying pan over low heat—drive off moisture
- Store
[Experience / Manufacturing] Can be done outdoors on the day
- Place dry-roasted peels in a measuring cup
- Pour in melted MP base to let compounds seep out
- Remove peels (with chopsticks or a spoon)
- Mix in matcha powder—adding color and fragrance
- Pour into shuriken mold
- Set and complete
Tools: frying pan, measuring cup, shuriken mold, portable gas stove
Ingredient Synergy
- Banana peel extract: tannin (astringent), lutein & polyphenols (antioxidant), moisturizing, antibacterial
- Matcha: catechin (antibacterial), chlorophyll (deodorizing & purifying), tannin
- Both banana peel and matcha contain tannin—they are chemically complementary
Iga × Kyoto: The Story the Ingredients Tell
Peel extract from Iga Ninja Banana (NPO Iga no Tomo, agri-welfare, pesticide-free) × matcha from Minamiyamashiro (Michi-no-Eki, ranked #1 in Japan)
Just reading the ingredient label tells the story.
Without explanation, Kyoto and Iga are connected inside this soap.
Connection to Pearl Soap
- Soap with a story as a shared concept
- Experiential distribution and gift applications
- QR code imprint linking to "the history of shuriken" and "a message of peace"
- If Pearl Soap tells a story of "rebirth from loss," Shuriken Soap tells a story of "peace from conflict"—both rest on the same philosophy of prayer embodied in form
Why TokiStorage Is Here
| Scale | Theme | |
|---|---|---|
| Pearl Soap | Personal | Preserving the memory of a loved one |
| Shuriken Soap | Humanity | Preserving the prayer for peace |
The scale differs. But the structure is the same—delivering prayer embodied in form across time. TokiStorage is the only entity that can handle both.
Shuriken were born 500 years ago. Eighty years since the war. And 1,000 years from now, this prayer will still remain. Soap dissolves and disappears. But stories do not. By recording through TokiStorage, the prayer of this shuriken soap project—who made it, what they wished for, what hands it passed through to be born—endures forever.
Soap dissolves and disappears. But prayers do not.
Carrying the wish of 80 postwar years 1,000 years into the future.
TokiStorage—records, for everyone.
Reference: Iga Tourism Resources
- Iga-ryu Ninja Museum (Ueno-Marunouchi, Iga City)
- Iga Ueno Castle
- Basho Memorial Museum (birthplace of Matsuo Basho)
- Iga-yaki Traditional Industry Hall
- Shuriken-throwing experience facilities (multiple)
Turning shuriken into soap is not a denial of weapons.
It is the succession of a conviction.