日本 にっぽん文徳 もんとく天皇 てんのう実録 じつろくでしょう
nippommonto kutenno uji tsurokudeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 日本文徳天皇実録

1. Probably the Japan Book of Emperors' Records.

Polite
Presumptive
Conjecture