koutaro, original, 1girl, arm support, ass, bare shoulders, bdsm, between legs, blue one-piece swimsuit, blush, bondage, bound, brown eyes, brown hair, cameltoe, chair, clenched teeth, crotch rope, desk, from behind, hair ornament, long hair, looking at viewer, loose socks, multicolored hair bobbles, old school swimsuit, one-piece swimsuit, one-piece tan, open mouth, rope, school chair, school desk, school swimsuit, shoes, socks, solo, swimsuit, tan, tanline, teeth, uwabaki, white socks