おうにしようくろまぐろでしょう
大西洋黒鮪でしょう
ōni shiyō kuromagurodeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of たいせいようくろまぐろ

1. Probably bluefin tuna.

Polite
Presumptive
Conjecture
Usually Written in Kana