Letter Left Unsent Cafe Illustration

Create a stylish vertical 3:4 anime fashion illustration in expressive ink-and-watercolor style, set at a small cafe table by a window. Show a young woman named {argument name="character name" default="Saiyu"} seated in three-quarter view, wearing a wide black hat, short tousled {argument name="hair color" default="ash-brown hair"}, a black off-shoulder camisole dress with thin straps, a black choker, round black earrings, and glossy black nail polish. Her face is intentionally covered by one large centered opaque square censor block in a warm taupe-to-brown gradient, hiding most facial features while leaving part of one eye, hair, hat, ear, and shoulder visible. Her right hand reaches toward a black sealed envelope on the table; the envelope has exactly 1 round yellow lemon-slice wax seal. Beside it is exactly 1 tall clear glass of dark iced drink with exactly 1 black straw, exactly 1 yellow lemon wheel garnish on the rim, and exactly 1 yellow circular emblem printed on the glass. Use a limited palette of cream, black, charcoal, muted brown, and bright lemon yellow accents. Compose the scene with a dramatic diagonal black window frame on the left foreground, blurred yellow flowers and leaves outside the window, a white tabletop with rough dry-brush shadows, and sketchy black ink borders. The mood should feel like a captured decisive moment, titled conceptually {argument name="scene title" default="Letter Left Unsent"}: intimate, fashionable, bittersweet, and cinematic. Add a small subtle watermark-like signature text {argument name="signature text" default="SAIYU。"} in the bottom-right corner. Keep the illustration loose and painterly with visible brush texture, high contrast black shapes, soft cream background, and no extra characters or readable text beyond the signature.