I read it once and can't remember the name of it.
The main character is at work when she is contacted by this company who need her help training/taming these men to be pets. They came from an island the company owns and each "group" has different attributes but all are very dangerous.
The first one is very beast like and constantly carries around a gun.
Another one hypnotises her and is going to let her starve to death before she "tames" him.
[/spoiler] I'm pretty sure in the end the first one comes back and wants to stay with her[spoiler]

Anyway if anyone knows what this is please tell me the name! Thank you