だい日本 にっぽん ゆたか秋津洲 あきつしまだったら
dainippon'yutakākitsushimadattara

Noun
Da Copula

The "-tara" conditional form ("if/when…") of 大日本豊秋津洲

1. If it were Great Japan, the abundant autumn land…; If Great Japan were the land of abundant autumn…

Tara Conditional