Private detective Goro has come to Sakurajima, a volcanic island in southern Japan, in search of a missing person or, as the Japanese say, someone who has "evaporated". In the course of his investigation, he crosses paths with three friends: Toshie, Moe and Mayumi. They are as interested in him as they are in everything new on the island. Meanwhile, the volcano is watching everyone with a smirk, exhaling its vapours and preparing for the big eruption.

"An unusual detective arrives on a volcanic island in the south of Japan, searching for a missing person. As time goes by, he gets to know the islanders, who seem to be keeping a secret. Like the vapours of the volcano."