Nihon kaisui

What Nihon kaisui does

Nihon Kaisui Co., Ltd. (株式会社 日本海水) is a Japanese diversified chemicals and consumer goods manufacturer wholly owned by Air Water Group (TSE-listed parent since September 2007). The company is organized around a vertically integrated seawater-resource platform, producing salt and downstream products across salt, environmental chemicals, power, food, agriculture, and aquarium businesses. Consolidated revenue was ¥53,125 million for FY2025 (year ended March 2025) with 731 employees as of March 2026.

The company's core competency is salt manufacturing using Japan's first ion exchange membrane method, which removes contaminants at 1/10,000,000 mm precision while concentrating seawater. It operates two major salt production facilities—Ako (Hyogo, 230,000 tons/year) and Sanuki (Kagawa, 190,000 tons/year)—making it the only domestic salt producer with a dual coastal-base configuration, supplying B2B food manufacturers (soy sauce, miso, pickles, seafood) via direct enterprise sales and B2C household consumers through Rakuten/Yahoo Shopping e-commerce and retail. Beyond salt, the company operates the READ series of rare-earth adsorbents for treating arsenic, fluorine, boron, and heavy metals; magnesium hydroxide slurry (S-35) for flue gas desulfurization at a documented 30-40% cost reduction versus caustic soda; Weeks-series soil stabilization materials; and AquaIntec's water/sewage engineering. Adjacent businesses include biomass and natural gas cogeneration at Ako, the Kanda Biomass JV in Fukuoka, potassium chloride fertilizer (2,800 tons/year from bittern), Urashima nori/furikake/ochazuke production at Kumamoto, AW-Water mineral water distribution, and an aquarium business centered on SEALIFE artificial seawater and stakes in átoa and Shikoku Aquarium.

Go-to-market is multi-channel: enterprise field sales for industrial salt; inside sales and inquiry-based technical specification handling for READ environmental products; marketplace e-commerce (Rakuten, Yahoo Shopping) and physical retail for household salt and food; and tank-lorry direct delivery of magnesium hydroxide slurry. Pricing ranges from listed unit prices for consumer SKUs (e.g., 380 yen for 80g Topping Salt) to inquiry-based multi-year contracts for industrial salt and chemical products. A June 2026 disclosure of inappropriate accounting and a May 2026 officer structure change represent a material governance risk to the operating profile.

Name

Nihon kaisui

Legal name

株式会社 日本海水

Website

https://nihonkaisui.co.jp

Company type

Private

Founded year

1995

Operating status

Operating

Headcount range

501–1,000 employees

Short description

Nihon Kaisui is a Japanese diversified manufacturer wholly owned by Air Water Group, producing salt (420,000 tons/year capacity across two factories), environmental water-treatment chemicals (READ series), magnesium hydroxide, biomass power, potassium chloride fertilizer, nori/furikake food products, and aquarium-related seawater products for industrial, agricultural, government, and household consumers across Japan.

Ownership category

akta.pro rank

Product category

Salt and Seawater-Derived Chemical Manufacturing

NAICS

Chemical Manufacturing (325), Pesticide, Fertilizer, and Other Agricultural Chemical Manufacturing (3253), Polish and Other Sanitation Good Manufacturing (325612)

SIC

Industrial Inorganic Chemicals (2810), Chemicals & Allied Products (2800)

akta.pro primary industry

Salt & Salt-Based Seasonings (Sea Salt, Flake, Seasoned Salts) (AFAJANAE)

akta.pro secondary industries

Chlor-Alkali & Derivatives (IMAEAAAC), Salt Reduction & Sodium Replacers/Enhancers (KCl Systems, Salty Enhancers) (AFAJADAI), Seaweed & Dried Vegetable Snacks Manufacturing (AFAKAIAI), NPK & Compound/Blended Fertilizers (IMAEAEAD)

Keywords

• Salt manufacturing
• Water treatment chemicals
• Agricultural fertilizers
• Environmental remediation
• Seawater resource utilization

Headquarters

HQ city

Tokyo

HQ country

Japan

HQ region

Asia

Offices8 records

Markets served

GTM type

B2B and B2C

Offering type

Hardware or Manufacturing

Cost components

Operations, Supply Chain, Personnel, Infrastructure, Technology or R&D, Marketing or Sales

Revenue model

1. Salt Products: Domestic salt production and sales including household salt, industrial salt, snowmelt salt, boiler salt, and artificial seawater. Core business with leading domestic market share. Products sold under brands including Japanese Seawater Salt, Premium Salt, Topping Salt, Ako Salt, Sanuki Salt.
2. Environmental Products: Magnesium hydroxide slurry for flue gas desulfurization, water treatment agents (READ series), soil remediation materials (Weeks series), and wastewater treatment solutions. B2B sales to factories, wastewater treatment facilities, and environmental engineering companies.
3. Power Generation: Biomass and natural gas power generation at Ako Factory. Renewable energy sales from two biomass generators and two gas turbine generators. Joint venture Kanda Power biomass plant in Fukuoka Prefecture.
4. Food Products: Nori seaweed products and furikake under Urashima brand. Food products manufactured at Kumamoto Factory including premium nori, furikake, and ochazuke. Products sold through retail and e-commerce channels.
5. Agricultural Products: Potassium chloride (saltpeter/kalium) produced from bittern at Ako and Sanuki factories. Annual production capacity 2,800 tons. Sold to fertilizer manufacturers as agricultural fertilizer raw material.
6. Water Business: Sales of AW-Water mineral water delivery service (Air-Water Group). Sales of household water products and related goods.

Pricing tiers

Go-to-market motion3 records

Distribution channels6 records

Marketing channels8 records

Core offering

Nihon Kaisui manufactures and sells salt products derived from seawater resources, including household salt, industrial salt (standard and original branded), snow melting agents, boiler salt, and artificial seawater (SEALIFE). The company also produces environmental chemicals such as magnesium hydroxide slurry, READ-series adsorbents, and READ-CX coagulants for water treatment; agricultural inputs including Weeks-series soil stabilizers, SPEX-RE, weed control sheets, and potassium chloride fertilizer; plus food products (AW Water mineral water, Urashima nori seaweed). Manufacturing is centered at Ako (Hyogo) and Sanuki (Kagawa) factories with co-generation biomass power generation on site.

Product overview

Nihon Kaisui is a diversified Japanese chemical company specializing in seawater-derived products. The company operates two manufacturing bases in Ako (Hyogo) and Sanuki (Kagawa) producing salt products ranging from household table salts (和食塩, 豊塩, 焼塩) to industrial salts for food processing, boilers, and snow melting. Its environmental division offers water treatment chemicals including READ series adsorbents for heavy metals and fluorine removal, coagulants, and soil stabilization materials (Weeks series). The company also manufactures agricultural fertilizers (potassium chloride from bittern), distributes mineral water (AW・ウォーター), and sells seaweed/nori products under the Urashima brand. The product portfolio spans core salt products, environmental chemicals, agricultural inputs, food products, and water services, unified by seawater resource utilization technology.

Differentiator

Problem solved

Functional benefit

Brands

• 浦島海苔 (Urashima Nori): Seaweed, furikake, and ochazuke products from a over 100-year-old brand based in Ariake Sea, Kumamoto
• マリン・テック (Marine-Tech)
• AW・ウォーター (AW Water)
• アクアインテック (AquaIntec)
• READシリーズ (READ Series)
• Week sシリーズ (Weeks Series)

Products and services

• Household Salt (家庭用食塩)
• Industrial Salt - Standard (工業用塩 標準品)
• Industrial Salt - Original Branded (工業用塩 オリジナル品)
• Snow Melting Salt (凍結防止剤)
• Boiler Salt Granulated (ボイラー塩 造粒品)
• Artificial Seawater SEALIFE (人工海水 SEALIFE)
• Magnesium Hydroxide Slurry (水酸化マグネシウムスラリー)
• READ Series Adsorbents (READシリーズ吸着剤)
• READ-CX Coagulant (READ-CX凝集剤) Coagulation agent used in industrial and municipal water and wastewater treatment.
• Weeks Series Soil Stabilizers (Weeksシリーズ)
• SPEX-RE Soil Treatment (SPEX-RE)
• Weed Control Sheet (防草シート)
• Wood-Plastic Composite (木質プラスチック複合材)
• Potassium Chloride Fertilizer (塩化カリウム肥料)
• AW Water Natural Mineral Water (AW Water 天然水)
• Urashima Nori Seaweed (浦島海苔)

Quantifiable outcome

• 30-40% chemical cost reduction in flue gas desulfurization compared to caustic soda
• +3 more outcomes

Named customers8 records

Segments5 records

Ideal customer profiles5 records

Technology focussed No

API detail

Has API

No

API docs

API detail

Core technology

AI maturity

App detail

Feature5 records

Partnerships

Ten partnerships are on record, tiered core and minor.

• Air-Water Group (エア・ウォーター株式会社)coreStrategic or Co-development Partner · 1 September 2007Parent company since September 2007. Air-Water Group is a comprehensive company handling air, water, and related resources. Nihonkaisui operates as part of the group's 'seawater business' contributing to the group's earth-oriented business portfolio. Synergy in water business (AW-Water), R&D collaboration, and management policies aligned with Air-Water's 'rat colony management' philosophy.
• Aqua Intec Co., Ltd. (アクアインテック株式会社)coreStrategic or Co-development PartnerWholly-owned subsidiary since July 2013. Industry-leading下水道 pipe renewal technology. Provides water treatment facility engineering and urban infrastructure development. Contributes to safe and comfortable city development.
• Nihonkaisui TTS Kanda Power Co., Ltd. (株式会社日本海水TTS苅田パワー)minorStrategic or Co-development PartnerJoint venture biomass power plant (68% Nihonkaisui, 30% TTS Planning, 2% Takuma). Kanda Biomass Power Plant in Fukuoka Prefecture contributes to local renewable energy production and decarbonization.
• Marine Tech Co., Ltd. (マリンテック)minorStrategic or Co-development PartnerSubsidiary providing artificial seawater products under SEALIFE brand for marine aquariums and aquaculture. Also produces marine fish feed and aquarium equipment.
• Kyushu Salt Co., Ltd. (株式会社九州ソルト)minorChannel Partner/ Reseller/ DistributorRelated company with 23% ownership stake since December 2010. Salt trading and distribution in Kyushu region. Handles salt imports and domestic sales.
• Japan Salt Association (日本塩協会)minorStrategic or Co-development PartnerEstablished April 2024 with other major domestic salt manufacturers. Purpose: address carbon neutrality challenges and promote domestic salt awareness. Joint industry initiative for public relations and policy advocacy.
• Ibaraki University Agricultural DepartmentminorStrategic or Co-development PartnerAcademic partnership since February 2011. Joint research on tomato cultivation using 'Umi no Megumi' bittern additive to increase sugar content. Collaborative crop enhancement research using seawater derivatives.
• Nihon MSM Salt Co., Ltd.minorChannel Partner/ Reseller/ DistributorBusiness partnership established October 2013. Industry-leading imported salt processing technology. Collaboration for expanded salt product offerings.
• Shikoku Aquarium (四国水族館)minorStrategic or Co-development PartnerInvestment in Shikoku Aquarium (opened in Kagawa Prefecture near Sanuki Factory). Company booth exhibits at aquarium entrance. Products sold as local souvenirs. Business expansion through aquarium operations.
• Kobe Port Museum / átoaminorStrategic or Co-development PartnerInvestment in Kobe Port Museum development. Aquarium 'átoa' operated within the museum. Further expansion of aquarium business and artificial seawater sales.

Scale indicators6 records

Recent moves11 records

Expansion highlights6 records

Direct peers

• Organo Corporation: Japanese specialty water and wastewater treatment company. Comparable in industrial water treatment chemistry and ultrapure water systems, overlapping with Nihonkaisui's READ series adsorbents.
• Kurita Water Industries: Japan-listed water treatment chemicals and facility operator. Direct peer in adsorption/coagulation chemicals and engineering services, including similar semiconductor and power plant customers.
• K+S AG: German producer of potash, salt, and magnesium products. Closely comparable to Nihonkaisui on salt-plus-fertilizer mix and magnesium derivatives, with overlap in agricultural inputs.
• Compass Minerals International: US-listed salt and specialty minerals producer with salt, sulfate of potash, and de-icing products. Direct peer in industrial/de-icing salt channels and a key comparator for Nihonkaisui's bulk salt business.

Others

• Yara International: Global nitrogen fertilizer producer with growing specialty and sustainable agriculture offerings. Less direct than K+S or ICL but relevant as a benchmark for agricultural input economics and potassium/nutrient product positioning.

Broad incumbents

• Tosoh Corporation: Major Japanese chemical manufacturer with chlor-alkali, vinyl, and specialty chemicals. Shares the ion exchange membrane technology lineage relevant to Nihonkaisui's salt production and broader inorganic chemicals space.
• Morton Salt: Established North American salt brand covering household, industrial, and de-icing salt. Comparable consumer-facing salt portfolio and brand-led marketing approach to Nihonkaisui's household salt line.
• Nippon Shokubai: Japanese specialty chemical company producing organic and inorganic chemicals, including water treatment polymers. Comparable as a domestic Japanese chemical manufacturer with environmental/specialty exposure.
• ICL Group: Israeli specialty fertilizer and minerals producer with potash, phosphate, and specialty plant nutrition products. Overlaps with Nihonkaisui's KCl fertilizer and bittern-derived agricultural products.
• Tokuyama Corporation: Japanese chemical company producing basic chemicals, specialty products, and cement. Comparable as a diversified domestic Japanese inorganic/commodity chemical producer with environmental and industrial portfolios.

Market position

Strengths5 records

Weaknesses5 records

Competitive moat5 records

Key risks6 records

Key highlights7 records

Customer concentration

Compliance9 records

Revenue estimate

Valuation estimate

Number of profiles

Profiles13 records

Subsidiaries5 records

Funding overview

Funding rounds

Investors

Funding detail is available on the Subscription and Enterprise plan.Contact sales →

M&A

Investments

M&A and investment is available on the Subscription and Enterprise plan.Contact sales →

Frequently asked questions about Nihon kaisui