1girl, b1ack_illust, black_hair, blue_dress, blush, dress, idolmaster, idolmaster_million_live!, idolmaster_million_live!_theater_days, looking_at_viewer, nakatani_iku, neck_ribbon, pinafore_dress, red_headwear, ribbon, shirt, short_hair, simple_background, skirt_hold, sleeveless, sleeveless_dress, smile, solo, uniform_series_(idolmaster), white_background, white_shirt