It crept up on her. It didn't burst in her chest with a flashy, garish firework of emotion. It bloomed within, a slow, torpid swelling of love, gratitude, and acceptance as she was on her way to sleep one night. A gentle thrum that beat with her heart, it grew the tiniest bit each time he laughed that laugh— the one that meant whatever had caused it was truly a piece of comedic genius— or flashed a grin so wide it seemed to bunch up to his eyes.
It grew; perhaps it had been budding from the very first time she saw him. Or maybe from the very first time he saw her.
She didn't notice when she stopped having crushes on other guys, or when she began to compare them to him, though the latter had to have resulted in the former. She didn't detect when she started to lean towards him naturally, and away from Ron, or that the two of them were quickly becoming incredibly close. It never dawned on her that the quips and whispers around and behind them may have an inkling of truth.
No, Hermione Granger most certainly did not realize that she was falling in love with Harry Potter.
But the one thing she didn't notice either, was that Harry Potter was falling in love with Hermione Granger.
A/N: A little drabble for Harry and Hermione. I imagine that they would have fallen in love slowly and over time.