1boy, 1girl, age_difference, akizuki_ritsuko, akizuki_ryo, antenna_hair, bare_shoulders, blush, braid, braided_ponytail, breasts, bright_pupils, brown_hair, chiaki_rakutarou, cleavage, collarbone, cousins, dress, embarrassed, full-face_blush, glasses, green_pajamas, hand_on_another's_shoulder, idolmaster, idolmaster_(classic), idolmaster_dearly_stars, large_breasts, looking_at_viewer, pajamas, purple_dress, siblings, simple_background, sitting, smile, white_background, yokozuwari