Minimalist graphic design poster, Japanese style, risograph

Minimalist graphic design poster, Japanese style, risograph screen printing texture, subtle noise grain, large blank negative space. Abstract flat illustration, several high-saturation purple distorted onion shapes, solid color blocks, no gradients. Plain pure white background. Bold black sans-serif text at bottom left: "洋葱 Onions". Clean layout, limited color palette, print art, sharp flat shapes, poster art, 2D, no shadows.