os-tan
2k-tan, xp-tan
sugimura tomokazu
2000s (style), 2girls, bare shoulders, black hair, blue background, blue eyes, blue hair, blue one-piece swimsuit, blush, bow, bowtie, breasts, calendar (medium), character name, covered navel, covered nipples, crossed arms, december, detached sleeves, glasses, gradient background, hair ornament, juliet sleeves, large breasts, long hair, long sleeves, looking at viewer, maid headdress, mechanical ears, multiple girls, one-piece swimsuit, open clothes, parted lips, puffy sleeves, rimless eyewear, school swimsuit, see-through, shirt, short hair, sidelocks, sleeveless, sleeveless shirt, swimsuit, swimsuit under clothes, taut clothes, taut shirt, upper body, very long hair, wing collar, x hair ornament