This route is for how you make Ashley your willing slave.
Note that this is just a general outline for the route. It is not a walkthrough.
Willing Slave Ashley (?)
(The reason it says (?) is because there's only a single scene present, so it's unknown if she actually becomes your willing slave, though it's highly implied).
The Protagonist returns home having enslaved Julia and meets with Ashley, who reveals that when Julia was fixing her mind, she also made it possible for Ashley to become the Protagonist's slave.
The Protagonist asks if she is the Protagonist's slave, but Ashley seems unsure about it.
The Protagonist is given two options: use magic on her or keep her as she is and enslave her.
Choosing the former makes her a regular slave.
Choosing the latter makes her the Protagonist's (presumed) willing slave.