Improvements!

Thanks to Jawanaut, I was able to get more insight on how to improve the functionality of this template.

Here are the changes:

1. I added a Character for Yuki. When we don't know his name, his display name is "stranger". Once he reveals his name, the character name will be changed to "Yuki".
2. I updated the screen to show Zeil and Yuki's names instead of "girl" and "boy".
3. I simplified the StaticValue code. It can now be found in the screen code instead of the LoveInterest class.