弘仁 こうにん貞観 じょうがん時代 じだいでしょう
kō ninjōganjidaideshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 弘仁貞観時代

1. Around the Koken/Tempyo period.; Likely the Koken/Tempyo period.

Polite
Presumptive
Conjecture