To stand upon the shore and gaze after a boat that disappears behind distant islands. This image, offered centuries ago by the great Noh master Zeami Motokiyo, is not a description of a boat. It is a portal. It is an invitation to feel the profound, lingering beauty not of the object itself, but of its vanishing. The meaning lies in the wake, in the vast and silent space the boat leaves behind, and in the wordless, mysterious emotion this evokes in the observer. This is the world of Yūgen (幽玄).