You could do a two sided love story, but neither parties realise the love of the other
#Trying to think of prompts
sullen heath
Seems plain, but if you add a little flair, it’ll capture some attention. Plus it fits the high school emotion
rich axle
can always just do an imagery of a field or somthing of the sorts if you dont want it to be sad, works most of the time for me.
brisk owl
Some of my ideas are conveying a childhood memory that can have sadness, but it has a bittersweet mood too. Also you could write a poem about your favorite fictional character