"Hey guys," Ron clapped both of them on the back. "We're happy you're here. We needed some more Gryffindors. Between you and me, we were beginning to get outnumbered by students from the other houses. Welcome to the Room of Requirement"
The Room was beautiful, high ceiling and tinted blue, seemingly with the dust of all of the spells being practiced by the students of the DA, around thirty of whom were practicing at this particular moment. Y/N was floored. It was beautiful, so many people working together to really learn magic in spite of the horrid Umbridge.
"Y/N," he heard her voice behind him, and the sound of her saying his name made him realize how long it had been since the last time she'd said it. 
"Hermione," he opened his arms to hug her. Surprise passed across her face, but it was quickly replaced by that look again, that one she always had when she saw him.
Holding her was like coming home. He couldn't remember the last time it had happened either. He quietly vowed never to let so long go between them touching each other again.
"It's really good to see you here," she breathed into the hug, just near his ear. He couldn't even conjure an answer. The joy overwhelmed him too much.
A crash across the room brought him back to focus. Harry had just performed a spell, knocking another student against the opposite wall.
"Woah-"
"It's okay," she said. "I won't be teaching you combat today actually. Harry told me to try working with the new recruits on their Patronus spells. In case Umbridge really decides to let the Dementors onto school grounds."
"Would she really do that?" he said, trying to keep it cool but honestly a bit worried at the thought.
"We don't know," Hermione said, pulling her wand from the inside pocket of her robe. "But that's why I'm going to teach you. Just in case."
"Right," he pulled out his want to match her stance. "Whatever you say. I trust you."
That look again.
"Alright, so the movement is pretty simple," she said and showed him. She was right. It was a pretty standard cast.
"Oh," Y/N repeated her movement. "It's like the Riddikulus spell. They look the same."
She seemed very pleased. "Yes, precisely. I'd swear you're the only person other than me who paid attention to that reading."
He remembered that day, skipping class because his Boggart was Hermione herself, in pain.
"So then what's the catch?" He said, wand still at the ready. "You know, beyond the stance and the words."
"Well," she stepped closer to him, almost an imperceptible amount, "you have to think your Patronus to life with the happiest, most wonderful memory you have. So bright and beautiful that it'll cast away all of the darkness of the Dementor and guard you."
"What's yours?" He asked before he could stop himself.
She paused. "My Hogwarts letter." Another pause. "Realizing there were others like me."
Y/N nodded, long and slow.
"I don't know if I've got anything that compares to that."
"Oh, I'm sure you do," she said, her hands going to his shoulders as if to motivate him, sending energy through her fingers. He closed his eyes. 
He thought. Hard.
Nothing.
Again, imagining, painting the picture, feeling Hermione's hands on his shoulders, letting that feeling flood his body until he heard her gasp.
"A dog. A bloodhound."
He opened his eyes and, sure enough, a dog bounced around before him, silver and made of light. His Patronus. Ever since he'd met her, it had been easier to produce the Patronus the more memories they had made. Their first date had been all the fuel Y/N to make his Patronus conjuring skills stronger than ever; he had practiced both in training and on his own, a keen learner who liked to get ahead, much like his...girlfriend? Yes, much like his girlfriend...their personalities were so similar they were perfectly made for one another. So just thinking of her eyes, or her smile, and he could summon a Patronus even faster than the legendary Harry Potter. 
She smiled that winning smile of hers, all sunshine even during this middle-of-the-night training session. Of course she was pleased. Hermione was nothing if not determined. She was probably used to pulling all-nighters, because as hard as Y/N tried, he still was always a few points behind her in all their classes. That, and every time she put her hand up, he got too distracted to interrupt her or follow up with an equally brilliant answer of his own. Not that it was a problem of course, because he could just fold up a funny note mocking Malfoy's hair that day, or something similar, turn it into a magical paper plane, and send it over. First, she'd shoot him a mock-disapproving look; then she'd laugh and use some clever charm to make the note vanish. And then Y/N would put his hand up and get a few points for Gryffindor himself. 

"Not as adorable as an otter, I suppose," he said. "But just as loyal and adaptable."
"You're a quick learner," she beamed. "Harry is going to be really impressed."
He was grateful, really, that even though she was the brightest witch of her age, she hadn't quite mastered divination and the mind-reading capabilities that come with it. If she had, she would have seen, in his mind's eye, the happy image that had brought his Patronus to life.
Her, in the library, holding the violets he'd kept in his back pocket when he asked her to the Ball. Her smiling so wide, telling him that, in that moment, over anyone else, she was choosing him.