1. First, find Goethe in Mond City and click Dialogue. He asked us to give him some wood.

2. Then, attack the trees in the wild to get pine and birch.

3. Go back to Goethe and click "Deliver".

Then he will give us a second task and ask Mona for rent. We went to Mona's residence and clicked "Mona's Lab".

After no reply, we need to find her. Here are three options. Take the first library as an example: click "Knight Library".

6. Come to the center of the library hall and start the story automatically. We haven't met Mona.

7. Go upstairs and press "Willag" at the door.

8. Finally, go back to Goethe, click on the dialogue and complete the task of paying everything.