(Idk how she would greet people so it might be inaccurate)

A side character from "Nitro" by Guchiry

Lopt (ロプト, Roputo[?]), also known as "X X X X"

Side Character of the Guchiry song "Nitro"

I am John Shuichi Saihara Fyodor Dostoevsky Steve Smith Cat Johnson

From what we know currently, he is quite a pessimist and has a strong idea of "justice".

Protagonist of the Guchiry song "Nitro" 

Carl (シャーロ, Sharo)

He does not know that they are characters from a song. 

A character from the song Schadenfreude by Guchiry

Nikolai Gogol (ニコライ・ゴーゴリ,, Nikorai Gōgori?, Russian: Никола́й Го́голь) is a member of the Decay of the Angel. His ability is named The Overcoat. 

The Clown, Nikolai Gogol!

Poe is a detective from America who was "beaten" by Ranpo in an investigation competition six years prior to the events of the series. The defeat leads to him withdrawing himself from his personal connections and becoming extremely secluded and depressed. However, this defeat also inspired him to take back the life that he felt Ranpo had stolen from him. He then joined the Guild and came to Japan in order to challenge him directly.
(Francis Scott Key Fitzgerald is the leader of the Guild.)