1girl, o, amagami, armpits, arms_up, bed_sheet, bikini, black_hair, breasts, breasts_apart, cushion, frilled_bikini, frills, front-tie_bikini_top, front-tie_top, looking_at_viewer, lying, messy_hair, navel, on_back, small_breasts, solo, stomach, swimsuit, tanamachi_kaoru, thighs, upside-down, usurai_rairai