春秋しゅんじゅう戦国せんごく時代じだいなら
shunjūsengokujidainara

Noun
Da Copula

The "-nara" conditional form ("if/when…") of 春秋戦国時代

1. If/when the Spring and Autumn and Warring States period…; During the Spring and Autumn and Warring States period…

Nara Conditional