1girl, arknights, arms behind back, ball gag, bdsm, black hairband, black panties, blindfold, blush, bondage, border, bound, gag, gagged, grey background, grey hair, hairband, heavyrain (arknights), kneeling, long hair, navel, no shoes, outside border, panties, pasties, qianshibu, solo, stomach, tail, thighhighs, thighs, underwear, very long hair, white border, white thighhighs