TBM is a Tokyo-headquartered materials technology company that develops and manufactures LIMEX, a calcium-carbonate-based composite that the company markets as a sustainable alternative to plastic and paper. The core idea is to substitute limestone, which is globally abundant, for the petroleum derivatives in conventional plastics and the wood pulp in conventional paper, reducing both crude-oil and water inputs.
Founded in 2011 by Nobuyoshi Yamasaki, TBM has grown into one of Japan's most-watched climate-tech companies. The company operates a flagship factory in Shiroishi, Miyagi Prefecture, with additional capacity expansion announced in subsequent years.
Its product range covers LIMEX Sheet (a paper-like material), LIMEX Pellet (an injection-molding feedstock), and a growing line of food-packaging, business-card, and signage products.
TBM has raised multiple late-stage private financings led by Japanese institutional investors and government-affiliated funds, and has been frequently cited in Japanese policy circles as a poster child for the country's green transformation (GX) initiatives. The company has not yet listed publicly but has flagged a future JPX listing as part of its growth roadmap.
Its position straddles materials science, manufacturing, and circular-economy policy, making it a structurally different bet from the consumer-software-heavy Tokyo tech cohort.
TBM is interesting precisely because it sits outside the consumer-SaaS pattern that dominates Tokyo tech, and its corporate structure reflects the older Japanese norms more than the freee-Mercari-Sansan template.
KK with capital-intensive growth needs. TBM is a Kabushiki Kaisha, which is the right form for any company planning to raise priced equity rounds, eventually list on the JPX, and operate physical manufacturing assets that suppliers and lenders want to underwrite against a familiar legal vehicle.
A GK (Godo Kaisha) would be inappropriate here because GKs cannot list, and lenders financing factory equipment generally prefer KKs with a clear shareholder register and statutory governance.
Founder voting share patterns. Like most modern Tokyo KKs, TBM cannot deploy US-style dual-class shares because Japanese listing rules disfavour them. Founder Nobuyoshi Yamasaki preserves influence through pre-IPO ownership concentration, supportive long-term Japanese investors, and board composition.
This is the core reason some Japanese founders accept slower capital raises in exchange for retained operational control.
JPX Growth as the realistic listing destination. When TBM does eventually list, the most likely tier is JPX Growth (the post-2022 successor to Mothers), which is designed for high-potential but not-yet-mature companies. Migration to Prime would follow once the company satisfies a 10-billion-yen tradable market cap, 800-shareholder, and 35 percent free-float threshold.
The Mothers-to-Prime path is now the canonical Tokyo growth-tech route, with Mercari, freee, Money Forward, and Sansan having all walked it.
TBM expects to list on the JPX eventually, and only KKs can list. KKs are also the form that Japanese banks, suppliers, and equipment-financing lenders are most comfortable underwriting against, which matters for a manufacturing-heavy company. A GK would be inappropriate for TBM's ambitions even though GK incorporation is cheaper and faster.
Growth is the post-2022 successor to the old Mothers tier and is designed for high-potential earlier-stage companies. Headline thresholds include a tradable market cap of at least 500 million yen, at least 150 shareholders, a 25 percent free float, and the same audit-committee or three-committees governance options Prime requires. Companies graduate from Growth to Prime once larger thresholds are met.
For most materials and manufacturing categories there is no general foreign-ownership cap. The Foreign Exchange and Foreign Trade Act does require pre-notification for large stakes in sectors deemed national-security-relevant, which can include certain advanced materials, dual-use chemicals, and infrastructure-related processes.
Sustainable plastic alternatives are generally outside the restricted-sector list, but each transaction should be reviewed.
The 2006 Companies Act abolished the prior 10-million-yen minimum for KKs and the 3-million-yen minimum for what is now the GK form. Today a KK can be incorporated with 1 yen of paid-in capital. In practice 1 million yen is the working floor, and capital-intensive companies like TBM raise materially more before commencing factory operations.
