いろはがるたでしょう
いろは歌留多でしょう
irohagarutadeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of いろはカルタ

1. Probably Iroha-uta karuta.

Polite
Presumptive
Conjecture
Card Games
Usually Written in Kana