Fuji Smart ONSENSUI – The First Onsen Mineral Electrolyzed Water Machine: A Dual Breakthrough in Japanese Technology

When people think of Fuji Smart, they immediately associate it with Japan’s prestigious medical device brand, boasting over 71 years of global credibility. In 2025, the company marks a groundbreaking milestone with the launch of Fuji Smart OnsenSui – the world’s first electrolyzed water machine that combines precious Onsen mineral water with advanced alkaline ionization technology.

This innovation not only inherits the legacy of Japan’s 1,300-year-old Onsen heritage, but also ushers in a new era: Onsen – Super Hydrogen – Smart Technology. It’s a one-of-a-kind dual water solution that delivers comprehensive health benefits and a premium lifestyle experience for modern families.

1. Fuji Smart OnsenSui – A New Breakthrough in Medical Electrolysis Technology

Fuji Smart OnsenSui integrates two advanced technologies in one – fusing Japan’s ancient mineral-rich Onsen water with cutting-edge alkaline ionization. This creates a unique harmony between Japan’s timeless Onsen culture and modern medical science.

The birth of OnsenSui marks the sixth evolutionary stage in the history of medical electrolyzed water machines. Following generations of innovations—from basic electrolysis, to hydrogen-rich, super-hydrogen, and smart systems—Fuji Medical now ushers in the “Onsen – Super Hydrogen – Smart” era in 2025.

OnsenSui inherits and elevates the legacy of legendary models like Fuji Smart i8, known for its 16,000L filtration capacity and modern design, and Fuji Smart i9U, renowned for super-hydrogen technology and AI intelligence. Building on that foundation, OnsenSui makes a major leap forward by introducing genuine Onsen mineral water directly into the electrolysis chamber—a world-first innovation.

[ OnsenSui (2025) = Fuji Smart i8 + 1/3 Fuji Smart i9U + Onsen Mineral Water ]

This integration enables OnsenSui to generate water that is not only hydrogen-rich but also naturally infused with essential Onsen minerals, offering both health and experiential luxury previously only available at Japan’s famous hot spring resorts.

2. Onsen Hot Springs – Japan’s 1,300-Year Medical Heritage

For over a millennium, the Japanese have revered Onsen (hot springs) as a therapeutic treatment for both body and mind. Beyond bathing, the Japanese tradition also includes drinking Onsen water to absorb minerals directly from within.

When consumed, Onsen water benefits the stomach, liver, and digestive organs, promoting overall wellness much like bathing in the springs. Records of drinking Onsen date back to the 7th century, as noted in the Nihon Shoki chronicles during Emperor Jitō’s reign (690–697), where patients reportedly recovered from ailments after consuming this special water.

During the Edo Period (1650–1750), the therapeutic effects of drinking Onsen were documented in medical literature such as Ippon-do Yakusenzo (1738), laying the foundation for Onsen medicine. In the Meiji Era (1868–1912), German physician Dr. Erwin Baelz, regarded as the “father of Onsen drinking therapy,” advanced and systemized the practice scientifically. Today, drinking Onsen remains a cherished element of Japan’s wellness culture, alongside its globally famed bathing tradition.

3. Introducing the OnsenSui Series

The OnsenSui Series represents a special line that combines Japan’s advanced electrolysis technology with the healing essence of Onsen minerals.

The first model launched in Vietnam – Fuji Smart OnsenSui – is priced at 69 million VND, positioned as a premium limited-edition experience.

Its standout feature lies not only in the “2-in-1” technology – simultaneous super-hydrogen generation and Onsen mineral recreation – but also in its exclusive limited release: only 1,000 units available in 2025 across three sales phases.

From 2026 onward, Fuji Smart will expand into higher-end Onsen models priced from 100 million VND, marking a new era of authentic Japanese water wellness.

4. Fuji Smart OnsenSui – Genuine Value Defines Distinction

Buying an electrolyzed water machine isn’t merely a purchase—it’s a long-term investment in health. Fuji Smart OnsenSui stands as the top-tier choice thanks to its next-generation electrolysis technology and the trusted 71-year medical heritage of Fuji Medical Japan.

4.1. Exclusive Super Hydrogen Electrolysis Technology

At its core, OnsenSui features dual-chamber electrolysis, capable of producing over 1,000 ppb dissolved hydrogen. The integrated SH1 chip ensures stable performance and compatibility with various tap water sources, even hard-to-treat ones.

The machine also supports natural salt electrolysis to generate safe disinfectant water for daily hygiene—gentle for babies and effective as a chemical-free alternative.

4.2. Dual Medical-Grade Electrolysis Chambers

Hi Chamber: 2 specialized electrodes that boost hydrogen concentration

Ki Chamber: 3 ionization electrodes for acid-alkaline separation

A medical-grade membrane separates the chambers, guaranteeing long-term stability and safety.

4.3. Smart 4.0 Medical Electrodes

Equipped with five Smart 4.0 medical-grade electrodes, patented under Japan Patent No. 4914338, each crafted from pure medical titanium coated with medical platinum—never commercial alloys or magnesium.

In 2025, Fuji Medical introduced a Nano Cone unified structure, increasing surface contact by 5x for faster and more durable water generation. These electrodes last over 25 years (≈4,400 continuous hours) and operate at 250W electrolysis power while consuming only 0.4W in standby mode.

4.4. Fujisui F5 Medical Filter

The Fuji Smart double-core medical filter features 5 layers: non-woven fabric, granular activated carbon, fiber activated carbon, high-efficiency hollow fiber membrane, and Mt. Fuji Onsen mineral stone. It achieves 16,000L filtration capacity, 1.5–2x higher than typical machines, removing bacteria, chlorine, lead, PFAS, and heavy metals—while preserving beneficial minerals.

4.5. Water Output Quality

OnsenSui delivers 7 multifunctional Onsen water types:

• Onsen Hydro Water (4 levels, pH 8.0–11.0, H₂ 200–1020 ppb): antioxidant-rich for drinking, cooking, and washing produce.
• Purified Onsen Water (pH 6.5–7.5): ideal for baby formula and medication.
• Beauty Onsen Water (pH 4.5–6.5): for skincare and haircare.
• Sanitizing Onsen Water (pH 2.5–3.5): for disinfection, cleaning toys, and food sanitation.

Flow rate: 2.5–5.5 L/min (150–330 L/hr)—up to 10x faster than standard RO systems.

(Note: pH values may vary ±0.5–1.0 depending on input water quality.)

4.6. Smart AI & Advanced Features

The AI 800-level processor analyzes water pressure, TDS, and pH to automatically optimize hydrogen and alkalinity levels.
It includes Hydrogen Plus mode, Hi-Mode for low pH water, and 19:1 water-saving efficiency.
The LCD display provides real-time water type, pH, flow rate, and filter lifespan, while Super Smart auto-cleaning maintains performance and hygiene.

4.7. Elegant Japanese Design

Featuring a Hi-tech silver-white aesthetic, the OnsenSui offers a 65cm 360° stainless steel faucet, compact size (347 × 225 × 120 mm, 5.7 kg), and flexible installation (countertop or wall-mounted). It can even operate mechanically during power outages.

5. Why Choose Fuji Smart?

Choosing a Fuji Smart ionized water machine means choosing a trusted medical brand, not just a device. With over 71 years of expertise, Fuji Smart stands as a global symbol of family health and Japanese craftsmanship.

Backed by Fuji Medical Group, founded in 1954 in Osaka, the company now operates in 100+ countries, with 12 medical device factories and five global brands, including Fuji Smart.

Fuji Smart’s hallmark is its dual-chamber super-hydrogen technology (≥1000 ppb)—a technology owned by only three Japanese corporations. Its patented medical electrodes are manufactured in-house, unlike other brands that rely on imported components.

Moreover, Fuji Smart machines are officially certified medical devices regulated by the Japanese government—guaranteeing safety and reliability for every household.

6. Conclusion

Fuji Smart OnsenSui is not just an electrolyzed water generator—it is the fusion of Japan’s ancient Onsen heritage and modern medical technology. It delivers rare, mineral-rich, super-hydrogen water that enhances health, safety, and quality of life—surpassing ordinary alkaline water machines.

Choosing OnsenSui means choosing a premium, health-forward investment for your family. Don’t wait until your health is compromised—contact Fuji Smart today to own an authentic OnsenSui machine and experience Japan’s finest water wellness innovation at home.