1girl, 31reyo, arms_behind_back, bad_pixiv_id, blue_buruma, blush, buruma, feet_out_of_frame, flat_chest, gym_uniform, idolmaster, idolmaster_cinderella_girls, light_brown_hair, long_hair, looking_at_viewer, simple_background, smile, solo, sweatdrop, twintails, very_long_hair, white_background, yokoyama_chika