Toilets, seasoning and glass fibre: the Japanese companies quietly winning the AI boom
Three Japanese firms whose core businesses have nothing to do with computing have become unlikely stock-market stars, because their decades-old materials end up inside the chips that power AI.
Key points
- Toto's advanced ceramics revenue rose 34% and operating profit rose 42% in the financial year ended 31 March 2026.
- Nittobo's electronic materials segment contributed about 91% of the company's total net-sales increase in the same financial year.
- Ajinomoto's Healthcare and Others segment, which includes its semiconductor insulation film, posted a 45.1% year-on-year rise in business profit.
- Shares in Toto, Nittobo and Ajinomoto gained 78%, 63% and 61% respectively in the year to mid-2026.
- All three companies say AI server and data-centre demand is now a primary driver of their growth.
The companies making the most money from the AI boom are not always the ones building the models. Sometimes they make bathroom fixtures.
Toto, Nittobo and Ajinomoto are household names in Japan for very un-techy reasons: high-end toilets, textiles and MSG seasoning. Yet their shares have surged this year, first reported by CNBC Tech, because each company also makes a specialised material that ends up deep inside the chips powering AI data centres.
So what do toilets have to do with AI chips?
Nothing, directly. But the ceramics skills Toto built over a century of making sanitary ware turned out to be exactly what chipmakers needed.
Since 1988, Toto has used that expertise to make ceramic electrostatic chucks, a component inside semiconductor manufacturing machines that holds ultra-thin silicon wafers perfectly still while circuits are etched onto them. If the wafer shifts even a fraction, the chip is ruined. Toto says its ceramics help manufacturers get more usable chips from each batch.
For the financial year ended 31 March 2026, that advanced ceramics business posted a 34% rise in annual revenue and a 42% jump in operating profit. The housing business that made the company famous actually shrank. Ceramics pulled the whole company into growth almost single-handedly.
Toto was careful to say it has "absolutely no plans" to walk away from its original business. The chip sector swings sharply with economic cycles, and the steady income from bathroom fittings cushions those swings.
What about glass fibre and seasoning?
Nittobo's story starts with printed circuit boards, the flat green boards crammed with components inside every phone and laptop. The company has supplied specialised glass fibre for those boards since 1984 under the name T-glass. Now that AI servers demand ever-more-complex chip packaging, Nittobo's materials are in higher demand than ever.
Its electronic materials segment grew net sales by 20.4% and operating profit by 39.7% year on year. That single segment accounted for roughly 91% of Nittobo's total sales increase, generating an extra 5.5 billion yen (about 34 million US dollars) in profit.
Ajinomoto's connection is the strangest of the three. A byproduct from making MSG led the company's researchers to develop a thin insulating film, now called ABF (Ajinomoto Build-up Film), which went on sale in 1999. ABF is used between the layers of a high-performance processor, the main computing chip in a computer or server, to carry electrical signals without interference. As processors grow more complex to handle AI workloads, the number of ABF layers per chip increases.
Ajinomoto folds ABF into a broader segment rather than reporting it separately, but that segment's business profit rose 45.1% year on year and now accounts for more than a third of the company's total profit, having overtaken even the frozen food division.
| Company | Core product | AI-linked material | Share gain (2026) |
|---|---|---|---|
| Toto | High-end toilets | Ceramic electrostatic chucks | +78% |
| Nittobo | Textiles / glass fibre | T-glass for chip substrates | +63% |
| Ajinomoto | MSG seasoning | ABF insulation film | +61% |
What does this mean for ordinary people?
For most readers, the direct impact is zero. These are business-to-business supply chains, invisible to end consumers.
What the story illustrates is that the AI supply chain is far wider than the handful of chip designers and cloud companies that dominate headlines. Dozens of specialised materials, many developed for entirely different industries, quietly make modern AI hardware possible. If any of those materials become scarce or expensive, the cost flows up through server farms and eventually reaches the apps and services people use every day.
Watch for: price changes on cloud services or consumer electronics being attributed to component shortages. The component in question is often not a chip itself, but something like a ceramic chuck or an insulating film that most people have never heard of.
