kasai shin, original, bad id, bad pixiv id, 2girls, :d, bikini, black hair, blue bikini, blue eyes, blue one-piece swimsuit, cloud, contrail, day, digital media player, headphones, innertube, ipod, long hair, looking at another, multiple girls, one-piece swimsuit, one-piece tan, open mouth, pink eyes, short hair, side-tie bikini bottom, skindentation, sky, smile, striped bikini, striped clothes, swim ring, swimsuit, tan, tanline