koiwai yotsuba, yotsubato!, artist request, character request, highres, official art, 2girls, age difference, brown hair, child, flute, green hair, hat, instrument, multiple girls, outdoors, pointing, police, police uniform, policewoman, raglan sleeves, recorder, shirt, shoes, short hair, short sleeves, shorts, simple background, size difference, skirt, sneakers, t-shirt, whistle, white background