1girl, d, alternate_costume, armpits, arms_behind_head, black_eyes, black_hair, black_sports_bra, blush, breasts, collarbone, idolmaster, idolmaster_cinderella_girls, looking_at_viewer, navel, open_mouth, otokura_yuuki, short_hair, simple_background, small_breasts, smile, solo, sports_bra, stomach, tomajiyama, wet, white_background