1girl, animal_ears, balloon, bed_sheet, casual_one-piece_swimsuit, fake_animal_ears, flat_chest, fukumaru_koito, heart-shaped_innertube, idolmaster, idolmaster_shiny_colors, looking_at_viewer, lying, neckerchief, nonbire, on_back, one-piece_swimsuit, pillow, rabbit_ears, sailor_collar, smile, solo, swimsuit, thigh_strap, twintails, wavy_hair, white_neckerchief