The Adidas Ultraboost 21 Koi is a limited-edition running sneaker featuring a striking koi fish motif printed across the white Boost midsole and heel counter. The upper combines lightweight Primeknit+ with engineered mesh for breathability and adaptive fit, while the signature TPU heel cage provides lockdown and structural support. Three bold black stripes adorn the lateral side, contrasting elegantly against the light gray textured knit. A translucent TPU window on the heel reveals part of the Boost cushioning system, enhancing both aesthetics and performance. The outsole uses Continental™ Rubber for superior traction on wet and dry surfaces. Designed for urban runners and streetwear enthusiasts alike, this model balances responsive energy return with everyday comfort—ideal for city commutes, light jogging, or fashion-forward casual wear. The koi pattern symbolizes perseverance and good fortune in East Asian culture, adding cultural depth to its modern silhouette. Perfect for spring and summer styling, it pairs effortlessly with joggers, tailored trousers, or denim.