A waist-up, rear three-quarter view of an (extremely beautiful woman:1.4) aged 24, who is looking back over her shoulder with a (big joyful grin:1.4) and (teeth showing in a cute wide smile:1.3). She possesses a (refined beautiful face:1.4) with (sparkling expressive eyes:1.3) and long,soft, fluffy hair adorned with a delicate floral kanzashi hairpin. She is dressed in a (yellow-based yukata:1.3) featuring intricate golden goldfish swimming among flowing water and pale pink sakura petals, secured by a detailed obi sash. The scene is set at the Nagaoka Matsuri Grand Fireworks Festival, with massive, multicolored fireworks blooming across the night sky, casting a soft glow and rim light on her skin and hair. In the distant background, soft smoke and blurred festival lights create a dreamy depth of field. The visual style is a highly polished anime illustration with beautiful color harmony, volumetric lighting, and a romantic, magical summer festival atmosphere, blending breathtaking beauty with heartwarming joy.