⚠ Every Fab in One Country, Two of Them on a Fault LineHigh threat

Kioxia Holdings (285A) — threat to the moat

The filing says it plainly: Yokkaichi sits in an area of high earthquake and flood risk, and Kitakami in one severely damaged in 2011.

Kioxia's asset concentration is the most extreme in this collection, and the company's own risk disclosure describes the exposure in unusually plain language.

The concentration, in the company's own wordsYokkaichi, Mie - 6 fabs'High risk of earthquakes and floods'Kitakami, Iwate'Severely damaged by the 2011 Tohoku Earthquake'20 April 2026Response to a Tohoku earthquake25 June 2026Response to a Tohoku earthquake99.5% of non-current assets in Japan. No capacity has been announced outside it.
The risk disclosure names both sites and says exactly what is wrong with each.

Of ¥1,667,234 million of non-current assets at March 2026, ¥1,658,950 million were in Japan — against ¥1,986 million in North America and Europe and ¥6,298 million across the rest of Asia1. Nine plants, six of them on a single site at Yokkaichi in Mie prefecture and the remainder at Kitakami in Iwate2.

The filing then says this: the Yokkaichi plant is located in an area with a high risk of earthquakes and floods, and the Kitakami plant is located in an area that was severely damaged by the 2011 Tohoku earthquake3. The company issued responses to earthquakes in the Tohoku region on 20 April and 25 June 20264.

There is a smaller, closer precedent. Kioxia's own presentations have referred to the financial impact of a power outage at Yokkaichi in June 20195 — not a disaster, a power cut, and material enough to still be explained to investors years later.

What partly offsets it is that concentration is also efficient, and that the alternative — building a leading-edge flash fab outside Japan — would cost more and take longer than the risk it removes.

The number to watch is any capacity announced outside Japan. There is currently none. Until there is, the single-country exposure is the whole answer.

The number that tests this threat
Reported
Non-current assets outside Japan
0.5% — ¥8,284M of ¥1,667,234M

Nine plants, six on a single site at Yokkaichi and the rest at Kitakami. Kioxia's own risk disclosure states that Yokkaichi sits in an area of high earthquake and flood risk and that Kitakami is in an area severely damaged by the 2011 Tohoku earthquake; the company issued earthquake responses in April and June 2026. Watch for any capacity announced outside Japan — there is currently none.

Source: Kioxia Holdings, Annual Securities Report for the year to 31 March 2026 ↗
References
  1. ReportedNon-current assets of ¥1,658,950M of ¥1,667,234M in Japan, against ¥1,986M in North America and Europe and ¥6,298M across the rest of Asia.
    Kioxia Holdings Corporation, Annual Securities Report for the year from 1 April 2025 to 31 March 2026 (8th Period) — revenue ¥2,337,628M against ¥1,706,460M, gross profit ¥1,012,904M, operating profit ¥869,013M, profit for the year ¥554,490M; research and development cost ¥141,052M against ¥132,798M; purchases of property, plant and equipment ¥281,062M against ¥223,847M; operating cash flow ¥616,540M; proceeds from government grants ¥56,396M against ¥43,748M, from an approved ceiling of ¥150.0bn for flash production at the Yokkaichi and Kitakami plants with about ¥31.8bn not yet received. Revenue by application: SSD & Storage ¥1,362,638M, Smart Devices ¥759,978M, Other ¥215,012M — 'Other' including retail products and sales to the Sandisk group recorded through the three manufacturing joint ventures. Revenue by geography: Japan ¥263,252M, North America and Europe ¥1,217,643M, Asia ¥856,733M, with the United States ¥1,098,832M, China ¥381,857M and Taiwan ¥300,932M. Non-current assets: Japan ¥1,658,950M, North America and Europe ¥1,986M, Asia ¥6,298M. Major customers: Apple group ¥476,014M (20.4%), with the Sandisk and Dell groups omitted for the year as each fell below 10% of sales. Flash Partners Ltd., Flash Alliance Ltd. and Flash Forward LLC are accounted for as joint operations with 50.1% of the voting rights and equal decision-making rights shared with Sandisk. Net interest-bearing debt ¥552,085M against equity of ¥1,398,929M — a net debt-to-equity ratio of 0.39 times, from ¥931,035M against ¥737,565M and 1.26 times a year earlier; USD-denominated senior notes at 6.25% (2030) and 6.625% (2033); goodwill of ¥395,585M from the 1 June 2018 acquisition of the former Toshiba Memory Corporation. Bain Capital funds indirectly hold 21.87% and Toshiba Corporation 17.59% of outstanding common shares, both having sold substantial holdings during the year. Risk factors state that the Yokkaichi Plant is located in an area with a high risk of earthquakes and floods and the Kitakami Plant in an area severely damaged by the 2011 Tohoku Earthquake, and name US-China trade frictions and US tariff policy among factors that may materially affect the business. The company does not provide plans or progress reports for the overall fiscal year. — year to 31 March 2026 · publ. 2026-06 · source ↗
  2. ReportedSix of the nine plants are at Yokkaichi in Mie prefecture and the remainder at Kitakami in Iwate.
    Sandisk Corporation, Form 424B4 prospectus (SEC, CIK 2023554) — Sandisk and Kioxia operate three business ventures, Flash Partners Ltd., Flash Alliance Ltd. and Flash Forward Ltd. (collectively 'Flash Ventures'), across seven flash-based manufacturing facilities in Japan, six in Yokkaichi and one in Kitakami, with an eighth beginning operations in calendar year 2025. 'We co-develop flash technologies (including process technology and memory design) with Kioxia for Flash Ventures' use. We and Kioxia jointly own these co-developed flash technologies.' 'Substantially all of our flash-based memory is obtained from our joint ventures with Kioxia... While substantially all of our flash memory supply utilized for our products is purchased from these ventures, from time to time, we also purchase flash memory from other flash manufacturers.' Sandisk names Kioxia, Micron, Samsung, SK Hynix and YMTC among its competitors, and completed its separation from Western Digital in February 2025. — FY2025 · publ. 2025-05 · source ↗
  3. ReportedThe risk disclosure states Yokkaichi is in an area with a high risk of earthquakes and floods and Kitakami in an area severely damaged by the 2011 Tohoku Earthquake.
    Kioxia Holdings Corporation, Annual Securities Report for the year from 1 April 2025 to 31 March 2026 (8th Period) — revenue ¥2,337,628M against ¥1,706,460M, gross profit ¥1,012,904M, operating profit ¥869,013M, profit for the year ¥554,490M; research and development cost ¥141,052M against ¥132,798M; purchases of property, plant and equipment ¥281,062M against ¥223,847M; operating cash flow ¥616,540M; proceeds from government grants ¥56,396M against ¥43,748M, from an approved ceiling of ¥150.0bn for flash production at the Yokkaichi and Kitakami plants with about ¥31.8bn not yet received. Revenue by application: SSD & Storage ¥1,362,638M, Smart Devices ¥759,978M, Other ¥215,012M — 'Other' including retail products and sales to the Sandisk group recorded through the three manufacturing joint ventures. Revenue by geography: Japan ¥263,252M, North America and Europe ¥1,217,643M, Asia ¥856,733M, with the United States ¥1,098,832M, China ¥381,857M and Taiwan ¥300,932M. Non-current assets: Japan ¥1,658,950M, North America and Europe ¥1,986M, Asia ¥6,298M. Major customers: Apple group ¥476,014M (20.4%), with the Sandisk and Dell groups omitted for the year as each fell below 10% of sales. Flash Partners Ltd., Flash Alliance Ltd. and Flash Forward LLC are accounted for as joint operations with 50.1% of the voting rights and equal decision-making rights shared with Sandisk. Net interest-bearing debt ¥552,085M against equity of ¥1,398,929M — a net debt-to-equity ratio of 0.39 times, from ¥931,035M against ¥737,565M and 1.26 times a year earlier; USD-denominated senior notes at 6.25% (2030) and 6.625% (2033); goodwill of ¥395,585M from the 1 June 2018 acquisition of the former Toshiba Memory Corporation. Bain Capital funds indirectly hold 21.87% and Toshiba Corporation 17.59% of outstanding common shares, both having sold substantial holdings during the year. Risk factors state that the Yokkaichi Plant is located in an area with a high risk of earthquakes and floods and the Kitakami Plant in an area severely damaged by the 2011 Tohoku Earthquake, and name US-China trade frictions and US tariff policy among factors that may materially affect the business. The company does not provide plans or progress reports for the overall fiscal year. — year to 31 March 2026 · publ. 2026-06 · source ↗
  4. ReportedKioxia issued responses to earthquakes in the Tohoku region on 20 April and 25 June 2026.
    Kioxia Holdings news releases — 'Response to the earthquake that occurred on April 20 in Tohoku, Japan' (21 April 2026) and 'Response to the earthquake that occurred on June 25 in Tohoku, Japan' (25 June 2026). Kioxia's Kitakami plant is in Iwate prefecture, in the Tohoku region. — April and June 2026 · publ. 2026-06-25 · source ↗
  5. ReportedKioxia's presentations refer to the financial impact of a power outage at Yokkaichi in June 2019.
    Kioxia Holdings, FY2021 fourth-quarter financial results presentation — the company's reconciliation of non-GAAP measures refers to the financial impact of the power outage at the Yokkaichi plant in June 2019, alongside the acquisition of the former Toshiba Memory Corporation by K.K. Pangea and the purchase of LITE-ON's SSD business. — June 2019 event · publ. 2022 · source ↗
Sources
Generated September 23, 2026