うすばかげろうでしょう
薄羽蜉蝣でしょう
usubakagerōdeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of うすばかげろう

1. Probably a mayfly.; Possibly ephemeral.

Polite
Presumptive
Conjecture
Usually Written in Kana