Saitama Prefecture announced on August 3 that it is accepting applications for the third edition of CSUP (pronounced “C-Sup”), a business plan contest targeting startups working to advance the circular economy.
CSUP is a Saitama Prefecture programme that supports circular economy initiatives aimed at the efficient and circular use of resources. It invites startups from across Japan to submit business plans envisioning operations within the prefecture. Individuals hoping to start a business, second-generation entrepreneurs, in-house corporate ventures, and university spin-offs are also eligible to apply.
The application period runs from August 3 to September 18 (must be received by 5:00 p.m.). A first-round document screening will be held in mid-October, followed by a final-round presentation review on November 13. From among the finalists, the contest will recognise a Grand Prize winner (1 recipient, prize money ¥1,000,000), Excellence Award winners (2 recipients, ¥500,000 each), and a Special Award winner (1 recipient, ¥300,000). Award recipients will also receive support for developing their businesses within Saitama Prefecture.
In the two previous contests, a large number of awards went to businesses making use of waste materials and underutilised resources.
In the 1st contest (fiscal year 2024), GYXUS Co., Ltd., which operates a closed-loop (bottle-to-bottle style) recycling business for waste plasterboard, took the Grand Prize. The Excellence Award went to Sustainable Create Co., Ltd., which works on recycling used disposable diapers, and to J.C.T. Co., Ltd., which promotes extending the service life of wooden pallets and converting them into charcoal. The Special Award was won by Smoke-i-freet, which proposed a smoked-wood material made from soy sauce lees.
In the 2nd contest (fiscal year 2025), HUB&STOCK Co., Ltd., which purchases surplus construction materials and redistributes them, took the Grand Prize; the company has since redistributed more than 100 tonnes of building materials per year from within the prefecture. The Excellence Award went to Yamori Co., Ltd., which renovates vacant houses and offers them as rental properties, and to Smoke-i-freet, the 1st-contest Special Award winner. The Special Award was won by ASTRA FOOD PLAN Co., Ltd., which uses a proprietary “superheated steam cooking machine” to convert food residues into food powder.
Full details and application instructions are available on the official CSUP 3rd contest website.
【Press Release】Applications Now Open for the 3rd Saitama Prefecture Circular Economy Startup Business Plan Contest “CSUP”
【Reference Article】2nd Contest (Fiscal Year 2025) Award Winners
【Related Article】Saitama Prefecture Holds Circular Economy Promotion Business Contest
【Related Article】Saitama Prefecture Advances Circular Economy Promotion Centred on Existing Industrial Parks; Briefing Session Held July 28
【Related Article】Saitama Prefecture Launches Four New Subsidies for Circular Business, Covering Circular Design to Collaborative Business Creation

