Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Passage: Haɗa tsibirin Honshu da Hokkaido ta hanyar haɗin kai an yi la'akari da shi tun lokacin Taishō (1912<unk>1925), amma binciken da ya dace ya fara ne kawai a cikin 1946, wanda aka haifar da asarar ƙasashen waje a ƙarshen Yaƙin Duniya na II da kuma buƙatar saukar da waɗanda suka dawo. A shekara ta 1954, jiragen ruwa guda biyar, haɗe da Tōya Maru, sun nitse a Tsugaru Strait a lokacin guguwa, suka kashe fasinjoji 1,430. A shekara ta gaba, Kamfanin Jirgin Ruwa na Ƙasar Japan (JNR) ya hanzarta binciken ramin. Wani abin damuwa kuma shi ne karuwar zirga-zirga tsakanin tsibiran biyu. Tattalin arzikin da ke bunƙasa ya ga matakan zirga-zirga a kan jirgin Seikan Ferry da JNR ke sarrafawa ya ninka zuwa fasinjoji 4,040,000 / shekara daga 1955 zuwa 1965, kuma matakan kaya sun ninka sau 1.7 zuwa tan 6,240,000 / shekara. Tsinkayar hasashen zirga-zirgar jiragen ruwa tsakanin tsibirin da aka yi a 1971 ya yi hasashen karuwar ci gaba wanda a ƙarshe zai wuce damar kayan aikin jirgin ruwa, wanda yanayin ƙasa ya ƙuntata.  Tambaya: Me ya sa ya kamata mu damu?
karuwar zirga-zirga tsakanin tsibiran biyu