[1] Kurushima is situated some 240 metres (790 ft) off the coast of Shikoku's Takanawa Peninsula (高縄半島) at the entrance to Hashihama Port (波止浜港) in Imabari.

[1] It is a natural fortress with cliffs to the north shaped by the fast currents (some 8 knots (15 km/h; 9.2 mph) to 10 knots (19 km/h; 12 mph)) and rocks below; there is a settlement on the flatter land to the south, around a small bay.

[3] In the Edo period, together with nearby Oshima (小島), the island was part of Kurushima Village (来島村) in Matsuyama Domain, with an assessment of twenty-six koku, three to, and nine shō.

[2] Around the end of the Kyōhō era in the early eighteenth century there were some seventy-eight households, fifty-three of them of fishermen.

[2] By Shōwa 53 (1978) this number had dropped to thirty-nine households, primarily making a living by commuting to the local shipyards and line fishing.