3girls, ahoge, alstroemeria_(idolmaster), alternate_costume, ankle_strap, breasts, brown_hair, cleavage, collarbone, cushion, idolmaster, idolmaster_shiny_colors, knees_up, kuwayama_chiyuki, long_hair, looking_at_viewer, medium_breasts, multiple_girls, osaki_amana, osaki_tenka, sitting, smile, straight_hair, thigh_strap, underwear, underwear_only, very_long_hair, wakaayu3