Green Carbon Co., Ltd. (CEO: Jun Okita, hereinafter "Green Carbon"), which operates Japan's largest nature-based carbon credit creation and sales business, has partnered with Tokyu Corporation (President and CEO: Masahiro Horie, hereinafter "Tokyu") to launch a demonstration of a regional circular agriculture ecosystem combining "reclaimed water x biochar" in Miyakojima, Okinawa Prefecture. This initiative, supervised by Professor Takeki Toyoda of the Department of Biological System Science, Graduate School of Agriculture, Tokyo University of Agriculture and Technology, began at the end of April 2026. Miyakojima faces a serious issue of groundwater and ocean pollution caused by chemical fertilizers. In this demonstration, reclaimed water, purified from the wastewater of "Maipari," a tropical fruit orchard operated by the Tokyu Group in Miyakojima, will be combined with biochar, produced by carbonizing agricultural residue at high temperatures, and applied to sugarcane fields as agricultural material. Through this initiative, we aim to prevent groundwater and ocean pollution by reducing the use of chemical fertilizers, while also contributing to the environment through carbon fixation and carbon credit creation by utilizing biochar. Additionally, improvements in soil quality are expected to increase yields. ○ For inquiries regarding this press release and details, please click here: https://green-carbon.co.jp/contact/ ○ To download company profile of Green Carbon Co., Ltd., please click here: https://green-carbon.co.jp/download-form/ ◆ Background - Water Cycle Challenges in Miyakojima - Miyakojima is Okinawa Prefecture's largest sugarcane producing area, boasting the highest production volume in Japan at over 330,000 tons annually. However, due to the island's unique geology (Ryukyu limestone), chemical fertilizers and agricultural chemicals easily penetrate the ground, leading to serious groundwater and ocean pollution. Miyakojima accounts for approximately 24% of t