2girls, ahoge, ass, ball, beach, bikini, black_bikini, black_sclera, blue_skin, breasts, closed_mouth, colored_sclera, colored_skin, crossover, hair_ornament, huge_ahoge, innertube, lala_(monster_musume), large_breasts, leg_up, light_purple_hair, lindaroze, long_hair, lying, monster_musume_no_iru_nichijou, multiple_girls, neptune_(series), ocean, on_stomach, purple_hair, purple_sister, sand, sidelocks, sitting, smile, swimsuit, water, white_bikini