A projection onto a waterfall that is situated deep in the Mountains of Shikoku.

In complete darkness, light reflects only off the particles of water that make up the waterfall, and thus shining particles cascade down, creating a waterfall of light particles. The light of the shining waterfall illuminates the surrounding area.
In the darkness, the shining particles leave a light trail afterimage that appears to draw lines in space. From the combination of these afterimage light traces, the waterfall of light is born.