Dynamic Japan Soccer Poster

Create a dynamic vertical sports poster in a sharp Japanese football graphic-design style. Canvas: portrait 2:3 ratio, off-white paper background with slight grain. Main subject: exactly 1 black-and-white illustrated soccer player in Japan national team kit, jersey number jersey_number, captured mid-kick with one leg extended toward the viewer, dramatic ink splatter shading, messy black hair, and a soft square gray blur obscuring the face. Add exactly 1 black-and-white soccer ball in the lower-left foreground, flying outward with perspective. Behind the player, place exactly 1 huge bold black letter main_letter with a white outline and red offset shadow, partially covering exactly 1 large red sun circle centered behind the athlete. Surround the figure with explosive abstract geometry: diagonal blue speed bars, red and black streaks, yellow accent lines, thin technical drafting lines, halftone dot clusters, small square pixels, splatter marks, and angular shards radiating from lower left to upper right. Use a limited palette of black, white, deep royal blue, vivid red, and small yellow accents. Composition should feel like a modern Japan soccer campaign poster, high contrast, energetic, urban, and print-ready. Bottom right contains small date text date_text above a handwritten signature signature. No extra logos, no extra players, no additional readable text.