1girl, ashida_ichirou, ass, ball, beachball, blonde_hair, blue_one-piece_swimsuit, bow, character_name, closed_eyes, from_behind, hair_bow, happy_birthday, idolmaster, idolmaster_cinderella_girls, loli, one-piece_swimsuit, open_mouth, ribbon, sakurai_momoka, school_swimsuit, short_hair, smile, solo, swimsuit, thighs