安楽 あんらく椅子 いす探偵 たんていでしょう
anrakuisutanteideshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 安楽椅子探偵

1. Armchair detective, likely.; Probably an armchair detective.

Polite
Presumptive
Conjecture