The neighboring Aji Island used to belong to the town of Oshika, while Tashirojima was a part of the city of Ishinomaki.

[6] In 1602, all pet cats in Japan were freed by decree to counter the rampant rodent population that threatened the silkworm industry.

[citation needed] In 2011, the island was hit by the Tōhoku tsunami, which destroyed the harbor and caused the ground to subside, leaving the villages more exposed to both flooding during high tides and strong coastal winds.

The local cat population fled inland to escape the tsunami, and only a portion returned to the villages in the aftermath.

The tsunami also caused an outbreak of parva in the region, and at least 80 cats on Tashirojima were captured and vaccinated in a matter of days to forestall the disease.

Due to the loss of the harbor, which was used primarily by a ferry service and Tashirojima's small fishing industry, a number of fishers and their families moved away.

[2] By 2015, government workers had rebuilt much of the harbor to raise the coastline and stop the floods, but the island's fishing industry remained diminished.

[citation needed] There is a small cat shrine, known as neko-jinja (猫神社), in the middle of the island, roughly situated between the two villages.

[citation needed] In particular, these shrines and monuments are concentrated in the southern area of the island, overlapping with the regions where silkworms were raised.

[11] In May 2006, Terebi Asahi filmed an episode of Jinsei no Rakuen (人生の楽園) on the island, which mentioned the large cat population.

[12] In 2015, Landon Donoho, an independent filmmaker, crowd-funded the production of a documentary titled Cat Heaven Island.