Kammala wannan jumlar: A lokacin Yaƙin Russo-Japan na 1904-1905, an yi yaƙi na ruwa, Yaƙin Korsakov, a garin a watan Agusta 1904. A shekara ta 1905, Japan
ya ci Sakhalin a ƙarshen yakin, kuma an ba da Sakhalin ta kudu, ciki har da Korsakovsky, ga Japan a 1905 bayan da Rasha ta ci nasara a yakin. 'Yan Rasha sun ƙone garin katako kafin a mika su. A kan toka na Fort Korsakovsky Jafananci sun gina birni na zamani da aka yi da dutse tare da tituna da wutar lantarki, sun sake suna "Ōtomari" (大泊), fassarar kalmomin Ainu "Poro-an-tomari" (babban tashar jiragen ruwa). Garin ya kasance babban birnin lardin Karafuto na ɗan lokaci tsakanin 1905 zuwa 1907. Duk da yake a hannun Jafananci garin ya girma sosai. Gidauniyar azabtarwa a ƙarƙashin gwamnatin Rasha, Ōtomari ta ci gaba da aiwatar da aikin tilastawa: Jafananci sun kawo dubban 'yan asalin Koriya zuwa Ōtomari a matsayin ma'aikata. Yawan mutanen Koriya na Korsakov na yau sun fito ne daga waɗannan masu aikin tilastawa.