1girl, afloat, ahoge, arm_up, bare_shoulders, bikini, blue_neckerchief, blue_sailor_collar, blush, bow, breasts, brown_hair, closed_eyes, collarbone, full_body, hair_bow, hakozaki_serika, hand_on_own_head, idolmaster, idolmaster_million_live!, idolmaster_million_live!_theater_days, innertube, long_hair, lying, navel, neckerchief, on_back, open_mouth, sailor_bikini, sailor_collar, sailor_swimsuit_(idolmaster), small_breasts, solo, swimsuit, twintails, very_long_hair, water, white_bikini, yukiho_kotori