What I noticed first and foremost while watching this drama was the strong likeliness to Tsukasa Hojo's City Hunter.

The main character is a baddie with a soft heart working as an outlaw, weak with girls, children and old people, who ends up helping the FL out of a pinch. Just like Saeba Ryo.

We also get a nice and intriguing back story for the FL (just like Makimura Kaori).

Add to the mix some action /fighting scenes, humor and puns, banter, a slight romance, plus a support cast, and you get the perfect mix!

Some might find the FL annoying because of her values, but remember that imperfect characters are the best, because that leave place for them to grow.

As for the core mechanism used by the hero (threatening people, yes, that's the spoiler you're looking for, but wasn't sure it was one since it's mentioned in the title tbh) it was quite surprising and unusual, but nonetheless really fun!

A really fun ride from beginning to the end, and if you loved it, go watch Tantei ga Hayasugiru. It's also really fun in it's own way!