Spiber's brewed-protein scale-up bet: ¥35B debt, ¥5B transfer, special liquidation

Spiber makes 'Brewed Protein' fiber by fermenting sugar with engineered bacteria - a spider-silk-style structural protein it sells to apparel brands such as The North Face, with plans for foams and automotive materials.

That fermented 'Brewed Protein' could replace wool, silk and cashmere at scale: build capacity first, and costs would fall to levels that unlock mass fashion.

More than $640M raised by 2021 (C&EN), including about $230M arranged by Mitsubishi UFJ Morgan Stanley through intellectual-property 'value securitization'; investors included Cool Japan Fund, Carlyle, Goldwin, Komatsu Matere and Shima Seiki (WWDJAPAN).

Spiber was founded in 2007 by Kazuhide Sekiyama and Junichi Sugahara, graduate students in bioinformatics at Keio University's Institute for Advanced Biosciences. Its early material, Qmonos, shrank when wet - the spider-silk 'supercontraction' problem - which delayed a planned 2016 Moon Parka; researchers redesigned the amino acid sequence to make a non-shrinking material, and the jacket finally shipped in 2019.

The 2019 Moon Parka with The North Face Japan sold out quickly, and by 2021 C&EN reported more than $640M raised, a Thailand plant opening in Rayong and a planned US plant in Clinton, Iowa with ADM (a shareholder whose stake C&EN valued near $90M). Revenue never followed the capacity: FY2024 sales were ¥414M with a ¥29.5B net loss, FY2025 sales fell to ¥177M with a ¥43.8B net loss, and net assets hit minus ¥28.1B. When ¥35B of securitized loans fell due on 2025-12-28, Spiber began a private reorganization; on 2026-03-25 shareholders approved transferring the business to CRANE, led by Masaya Kawana, for about ¥5B, closing 2026-03-31.

The operating business - including the Spiber name - passed to CRANE (renamed Spiber) around 2026-03-31, and the founders are not part of the new management. The original company, renamed to hold structural-protein assets, will apply for special liquidation about two years after its US subsidiary is wound up.

Spiber's plan leaned on a cost curve: mass production would make fermented protein cheap enough to replace wool and silk, but FY2024 revenue of ¥414M stayed tiny against enormous fixed costs.

The funding was structured like a countdown: roughly ¥35B of its borrowings came due on a single day, 2025-12-28, through an IP-backed securitization vehicle, leaving no room for another slow year.

The technology genuinely delivered - the 2019 Moon Parka proved the supercontraction fix - but apparel buyers stayed premium and limited, far below the scale of the Thai and Iowa plants.

Skeptics flagged the gap early: C&EN's 2021 feature quoted analysts doubting volume production after what one called 'a long history of failing to achieve its goals.'

Spiber won the science but lost on timing: it built industrial plants and stacked ¥35B of debt on a future cost curve, and when demand stayed at pilot scale, a fixed maturity ended it.

As of 2026-09-02, Spiber's business continues under sponsor CRANE led by Masaya Kawana, which committed about ¥15B (¥10B working capital plus the ~¥5B transfer price) and took the Spiber name; founders Sekiyama and Sugahara are not in its management. The original entity now winds down subsidiaries, with special liquidation expected about two years after its US subsidiary's liquidation completes (Tokyo Shoko Research). Investor losses are booked: Komatsu Matere took a ¥1.2B special loss in October 2025, and WWDJAPAN says other shareholders will book losses in fiscal years ending March 2026.