Mitsubishi Goshi Kaisha bought the island in 1890 and began extracting coal from undersea mines, while seawalls and land reclamation (which tripled the size of the island) were constructed.
Mitsubishi Goshi Kaisha comprou a illa en 1890 e comezou a extraer o carbón das minas submarinas, mentres foron construídos diques e recheos de terra (que triplicaron o tamaño da illa).