The French had good relations with the local people who they considered to be in the very distant past of northern Chinese origin, describing them as intelligent, good-looking, and short in stature.

Lapérouse gives a very detailed description of his relations with these people in his work Voyage de Laperouse Autour du Monde, published in 1797.

[citation needed] Along with the rest of the southern portion of Sakhalin, it was placed under Japanese control by the Treaty of Portsmouth in 1905 and remained so until 1945, during which time it bore the name of Tomarioru (泊居), derived from an Ainu term meaning on the bay.

[citation needed] Tomari is one of the only Ainu place names in Sakhalin that wasn't renamed from the Japanese administration era.

The largest industrial facility in the town, a paper factory, went bankrupt in the mid-1990s; its collapse provoked a large emigration.