Rare Earths

Minamitorishima: rare earths under Japan's seabed

6 min read · Updated May 2026

Japan's rare-earth narrative centers on Minamitorishima — a remote island roughly 1,800 km southeast of Tokyo. Academic studies have estimated more than 16 million tonnes of rare-earth oxides in deep-sea mud surrounding the island, including elements critical to EV motors, defense electronics, and high-end magnets.

The resource is real. Whether it can be commercially extracted is a separate question.

Why this matters strategically

China currently dominates global rare earth supply. For Japan — a country reliant on imports for almost every critical input — having a domestic resource of this scale is a geopolitical asset, regardless of when (or whether) it can be commercialized.

The reality check

Test mining is targeted from 2026, but commercial extraction faces real challenges:

Engineering: Deep-sea collection, lifting from ~5,000m depth, and on-shore separation all need to work at scale
Economics: Costs need to compete with existing supply chains, especially Chinese refiners
Environmental: Permitting and sustainability standards for deep-sea mining are still evolving globally

The listed-name angle

Mining-tech and offshore-system names

For Minamitorishima specifically, the watchlist should focus on companies with disclosed links to deep-sea resource surveys, slurry lifting, offshore engineering, marine construction, or metallurgical processing — not generic trading-house exposure.

Toyo Engineering (6330.T): involved in technology development for recovering rare-earth mud from around 6,000m depth, including slurry / lifting system work.
Japan Petroleum Exploration — JAPEX (1662.T): participated in J-MARES and successor deep-sea resource survey initiatives related to Minamitorishima.
IDEA Consultants (9768.T): a construction and environmental consulting company linked to J-MARES / next-generation marine survey work.
Furukawa (5715.T): mining-machinery and resource-development technology angle; cited in Japanese market coverage as developing equipment for seabed mineral recovery.
MODEC (6269.T): offshore engineering expertise and participation in the University of Tokyo rare-earth mud / manganese nodule development consortium.
Pacific Metals (5541.T): downstream processing angle through commercial-scale polymetallic nodule smelting tests.
Toa Construction (1885.T): marine-construction angle; has worked on mud-disintegration / collection-related demonstration activity for rare-earth mud.

Why not generic trading houses here?

Trading houses may still matter in future supply-chain finance, offtake, logistics, or overseas procurement. But unless there is a disclosed Minamitorishima project role, they are too broad for this section. The rare-earth page should stay focused on the companies with a clearer connection to the actual seabed development chain.

Separate downstream angle

TDK (6762.T) and Shin-Etsu Chemical (4063.T) remain relevant to rare-earth demand through magnets and materials, but they are better treated as downstream demand beneficiaries rather than direct Minamitorishima development names.

How to think about this: rare earths are a slow-burn structural theme, not a near-term catalyst. The 2026–2027 test-mining milestones matter, but commercialization is still uncertain. For investors, separate direct Minamitorishima mining-tech exposure from broader downstream rare-earth demand exposure.

For educational purposes only. Not investment advice. Past performance does not indicate future results.