Motoi Yamamoto was a third-year student at the Kanazawa College of Art in 1996 when his younger sister died at the age of 24 — two years after being diagnosed with brain cancer. To ease his grief, and to make sense of various personal issues he faced on the periphery of his sister's death — such as the delay in approval of cancer drugs in Japan and the difficulty in choosing end-of-life care — he started working on a series of installations using these issues as motifs.

It was through such undertakings that Yamamoto came up with the idea of using salt in his works. Salt has a special place in the death rituals of Japan, and is often handed out to people at the end of funerals, so they can sprinkle it on themselves to keep evil spirits away.

Since 2001, he has been creating labyrinthine floor installations, filling a plastic bottle normally used for machine oil with white salt and using it as if it were a paint brush. One of the three works of his being exhibited at Hakone Open-Air Museum, titled "To the White Forest — Forest of this world/Forest of beyond," is an extremely elaborate, though ephemeral, creation.