I think "office lady" is a bit of an injustice. This is clearly the inner circle of a powerful syndicate. Miho is the don, obviously, Hana the consigliere, Yukari the underboss, while Saori keeps the accounts and fear of Mako keeps all the common foot soldiers in line.
"I was terrified of her. Everyone was terrified of Mako. I've seen grown men pull their own heads off rather than see Mako. Even Yukari was frightened of Mako."
"What did she do?"
"She used... sarcasm. She knew all the tricks - dramatic irony, metaphor, bathos, puns, parody, litotes, AND satire."