idolmaster, idolmaster (classic), kisaragi chihaya, tengu (tetuo kun), tetsuo kun, high resolution, simple background, white background, 1girl, alternative hairstyle, black bikini top, blue hair, breasts, brown eyes, chromatic aberration, cleavage, clothes pull, dark blue hair, erect nipples, erect nipples under clothes, eyebrows visible through hair, female, hair ornament, halterneck, head tilt, nipples, off shoulder, off-shoulder sweater, ponytail, small breasts, solo, sweater, sweater pull, tied hair, upper body