Bridgestone is promoting efforts towards sustainability across the entire value chain of tires, from "creating and selling" to "using" and "returning" raw materials, while establishing a unique sustainability business model that aligns with its business operations. Organic fiber reinforcements are mainly applied in the Body Ply and Cap Ply of tires, requiring careful selection of materials based on their functional roles in the tire. The primary materials that need to be made sustainable include polyester fibers (PET fiber is the main material used in tires), nylon fibers (Nylon66 fiber is the main material used in tires), and aramid fibers. There is an increasing focus among fiber manufacturers on exploring bio-based materials from the perspective of CO2 reduction, as well as considering recycled materials from the standpoint of resource circulation. We will present the challenges and the latest application status of these sustainable materials in tires. Additionally, in the recycling of used tires, we are advancing technological development through strong collaboration between industry, government, and academia. This is the content of the presentation on the latest developments in sustainability with regard to tires.