I think I saw the movie on Nickelodeon when I was little. I remember very little about it, but there was a little girl underwater (maybe in a yellow dress? Maybe named Dot? I have no idea... ), and I remember she was swimming near a whale, and at some point she stepped on a sea urchin or a shell, and then there was a black dot or hole on the bottom of her foot and it almost looked like black smoke or ink or something was coming out of her foot and the urchin maybe poisoned her?

Not Japanese
Australian,.

Try,.
Dot and the Whale


---