Unicorn likes a lot of things. The only problem is that the things he likes aren't exactly the same as everyone else's. 

Sparkles? He hates them!
Balloons? No, thanks! 

Cake? Yuck! 

But soon it will be Unicorn's birthday, and, oh no! 

That means all of the things Unicorn hates will be smooshed together and squeezed into the same day. 
This is a disaster! 
What on Earth is unicorn going to do?