Below is a walkthrough for the Mainz Mountain Path Monster Extermination support request in The Legend of Heroes: Trails from Zero.
Client: State Government
Salary: 2000 mira
When you reach the Mainz Mountain Path bus stop in area 4, take the northeastern path. In the next area, take the first path on the left.
At the dead end, approach the Fall Eagle and select to exterminate it.
This will begin a fight against 2 Fall Eagles. Defeat both of them to complete the quest! Make sure to report it to the terminal!