樺太からふと千島ちしま交換こうかん条約じょうやくでしょう
kara futo chi shimakōkanjōyakudeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 樺太千島交換条約

1. Probably the Japan–Soviet Exchange of Territories Agreement.

Polite
Presumptive
Conjecture