The Kikoman soy sauce bottle is the perfect example of iconic design, in that, you can't imagine a soy sauce bottle to be designed in any other way.
Ekuan managed to achieve something very special with it.
You can say that about literally everything he's ever designed. It's all iconic, and the best part is, you wouldn't be able to tell it was a Ekuan design by looking at any object without the knowledge before that he made it. Starting everything from scratch, and not having a style, is the best style a designer can have.