Create an adorable watercolor-style illustration of a koi fish pond on a white background, where the koi fish have an irresistibly cute appearance. The watercolor technique should be employed to achieve a soft and dreamy effect, with gentle brushstrokes and subtle color blending that adds to the overall charm. The koi fish should be depicted with chubby bodies, big round eyes, and playful expressions, giving them a lovable and endearing look. The pond should be adorned with lush water plants, su