1girl, barefoot, black bra, black panties, bra, breasts, brown eyes, brown hair, butt crack, closed mouth, from behind, hand on own chin, hiroki (yyqw7151), idolmaster, idolmaster shiny colors, large breasts, long hair, looking away, no shirt, panties, panties under shorts, red shorts, shorts, sideboob, simple background, sitting, solo, tsukioka kogane, underwear, white background