Here's a snapshot of Leo at the beginning of Stargirl:
And here's a snapshot of Leo at the end:
Sounds like coming of age to Shmoop. Over the course of the novel, Leo learns what it means to be an individual. Through his relationship to Stargirl, he figures out what's important to him, and what's right. Of course, he doesn't always make good choices, and he makes all kinds of mistakes. But he learns from them, and when we meet him as an adult, it's clear that his adolescent experiences have forever changed him.
We totally admit it: Stargirl definitely seems unreal. At times, even Leo has trouble believing she is genuine. At times, she seems almost otherworldly, and it's not like you hear about "star people" in everyday conversation. Nevertheless, Stargirl falls under the realism genre because it's a book about very believable teenage life. Characters speak and dress in an everyday way, and fall in love just like the rest of us.
Of course Stargirl doesn't do anything in an everyday way. She's just about as extraordinary as you can get. But she's totally real. We'll let Jerry Spinelli himself explain:
Stargirl is as real as hope, as real as possibility, as real as the best in human nature. Outrageous? I hope so. Thank goodness for the outrageous among us. I wish I were more outrageous, less predictable, more unrealistic. I understand that the story carries a whiff of fantasy, of the tall tale. The story, and in particular the character, are intended to raise dust in the corners of credibility, to challenge our routine ways of seeing ourselves. When Archie says to Leo, "She is us more than we are us," he refers to both her essential humanity and to our own often unrealized potential. Leo himself almost accuses her of being too good to be true, then later notes, "That was no saint kissing me."
What does it say about us if we believe such a person to be impossible? The message of the story is precisely the opposite: such a person is possible, and to the extent that Stargirl is us (Archie: "She's an earthling if ever there was one."), so are we. (Source.)
There you have it, folks.
Around Stargirl, Leo feels "nine ways at once." That rings a bell for those of us who have fallen in love. It's confusing, crazy, and awesome. Leo's relationship with Stargirl grows from an innocent crush to full-blown love, and then it all comes crashing down. Still, no matter its ending, the two of them were clearly in love, and that makes this book a romance, through and through.