Create an anime-style illustration of a boy with short, slightly messy dark hair

Create an anime-style illustration of a boy with short, slightly messy dark hair. He should be wearing an oversized blue denim jacket. The boy's expression should be one of happiness, with a big smile and his hands giving a thumbs-up. The background should be a plain, light grayish-blue color to keep the focus on the character. Ensure the drawing has a clean, detailed, and slightly pastel color palette to match the aesthetic of modern anime illustrations.