Haine Ren (Simdate Preview?)

Model: School DT Ren Haine 
Skydome by Ussy-P
Gun by amiamy111
So... I'm planning a sim date featuring Haine Ren. It'd be fantasy-school life-ish featuring the main character Ren who takes care of monsters that looms the school called Kage (shadow). I may be a little slow on making the game cause I'm pretty busy with a huge school project coming up, but I have to finish it before June.  
The thing is that I have the beginning, the first encounter, and the ending in mind but I have no idea what to put in the middle. Any suggestions or anything you wish to see in it? My head is burning from writing right now.

EDIT: Erm, here's the plot detail. So Haine Lin and Ren transferred from somewhere nobody knows. They aren't very nice to you and your friends, so your teacher put you in charge of showing him around the school. Ren keeps ignoring you. Then in the evening you realize you forgot your homework and bump into Ren fighting some kind of weird monster in the hallway. They go up to the roof, so out of curiosity, you follow him and learned his secret. And...that's where I got stuck. Any help please? *put on puppy eyes and blink rapidly*