My first ever Fairy Tail fanfic. X3 If the Fairy Tail fanfiction base wasn't so stunted I probably wouldn't have done this because art is more my thing, but I must do my part to spread the NaLu love! Please try to enjoy my poorly constructed and written one shot.

There had to be a reason that Natsu acted like he was about twelve, despite being nearly eighteen. The guild turns to Gazille for answers and they certainly weren't expecting the truth!

9:00 am; 1 hour

Gazille was… surprised to say the least. Never before had so many people crowded around him and none of them wanted to kill him. It was creepy. Oh, that Mirajane was too clever for her own good. Tricking him into revealing that he knew why Natsu had the mental age of a toddler and then bringing out the one weapon he had no resistance too.
"Please tell us Gazille." The Iron Dragon Slayer glanced down into a pair of liquid brown eyes that glistened with fucking tears. He groaned. "Levy… I already said it's kind of a secret." The Dragon Slayer, normally renowned for his cold attitude, resisted the urge to fidget uncomfortably as the girl's lip started to tremble.

He was strong.

He would resist.

He would persevere.

"Fine! Fine! I'll tell you! Just stop doing that!" As Levy's face split into a sunny smile Gazille looked away, feeling his face warm up. Stupid girl was too damn pretty. Unfortunately, to top off his already awful day, Mirajane picked up on it. "See!" The white haired woman poked his slightly red cheeks. "He's not stunted like Natsu! Explain Gazille!"

"Jeezus, woman get off me. I said I'd tell." Gazille glowered at everyone until his personal bubble was no longer invaded (no closer than five metres or I'll eat you) though Levy ignored this. Gazille in turn ignored the infringement and tried to look bored. "Fine, though this is tricky to explain." No one in this crazy guild seemed fazed. "Well, when Dragon Slayers hit about twelve they stop aging mentally. Their bodies continue to grow and crap." Gazille was not explaining puberty to them. "But when their bodies have finished with the changing stuff then their minds snap forward five years or so. It's a weird kind of survival thing. You never want to see a dragon having a teenage fit. So, I don't know what causes it, but their minds wait until they're able to handle being seventeen or eighteen. There's a twenty four hour period of hell while everything recalibrates and then you've got a normal person."

Everyone stared at him. Gazille stared back. Was the whole guild here? He could see everyone, apart from the Salamander of course. Lucy, Grey, Erza, Mira, Jet, Droy, Elfman, Macao, Cana… Levy. If you could name them they were there. He sighed. "If I was going to lie I'd come up with something better than that."
Levy frowned. "Is the process really bad enough to warrant that kind of time skip?"

"Yeah. Most of Phantom was totalled after I changed." As one the Fairy Tail members groaned. Master Makarov went pale and ordered another pint as Gazille beamed at them. Justice.

10:04 am; 2 hours

Lucy squirmed uncomfortably in her seat at the bar as Mirajane smiled at her. Normally this wouldn't have been so unusual but Lucy had been here for ten minutes now and Mira hadn't stopped smiling even for a second. "Okay, Mira, what is it? Is there something on my face?"
Mira laughed. "Why Lucy, what are you talking about?"
Lucy gave her an unimpressed look.
"Ah, fine, fine. But don't you think it's exciting?"
"What's exciting?"
"Natsu's going to grow up soon! Isn't it amazing? My dreams have not been crushed by his idiocy!" The beautiful woman quickly calmed herself and smiled serenely at Lucy, propping her elbows up on the bar top. "Lucy, aren't you excited to see what Natsu will be like as a man, instead of a kid?"
"Well, a… a little I guess." In truth Lucy was very interested. Even if he acted like an idiot Natsu was a very handsome person, it was hard to not be even slightly curious. "Yeah, I guess I am a little. I wonder when it will happen."
Mira beamed at her. "Any day now, I'd expect. He's nearly eighteen after all. Actually now we mention Natsu, I'm surprised he hasn't been in yet. Could you go check on him?"
Lucy sighed. "Fine, fine, Mira. Though if he sets my hair on fire one more time you may never see him again."

Lucy knocked hard on Natsu's door, her pretty features set into a deep scowl. She'd been banging for ten minutes now and there was no way the Dragon Slayer had slept through that. He was always whining about how his hearing was better than normal people's so he didn't need her shrieking in his ear. Lucy opened her mouth and yelled, "NATSU! IF THIS DOOR DOESN'T OPEN NOW IT'S GOING TO BE SMASHED DOWN!" There were muffled groaning sounds from inside the house and a thumping noise generally associated with falling out of bed. Lucy frowned; he really had managed to sleep through her banging? Lucy realised that something was wrong even before Natsu was revealed to her, leaning on the door frame and generally looking like he'd go and get hit by a train just to end this suffering, but he was too feeble to get to the station. Lucy stared at him in horror before asking, "Natsu! What's wrong?"
"Don't feel so good."
Lucy frowned in sympathy. "You don't look so good either. Come on." The blonde girl grabbed his elbow and led him back into his room. "Let's see if I can help at all."

Once the pink haired boy was lying in bed again, occasionally letting out a soft moan of despair, Lucy set about getting him something to eat because Natsu certainly hadn't had anything since last night. True, she had limited experience dealing with sick people, but sick people liked soup didn't they? Simple. If only she knew how to set fire to soup.

Lucy gently put the bowl down on his bedside table and shook him awake. "Hey, Natsu. I've got you something to eat."
The famed Salamander sat up, eyes bleary and Lucy almost laughed. It was hard not to love Natsu when he'd just woken up; quiet and with the greatest case of bed head she'd ever known. The blonde patted his head lightly and laughed. "Come on! I've got you soup."
Natsu growled and rubbed his eyes. "Lucy?"
"Yup!" The girl laughed and turned to pick up the soup. "It's me, so hurry up and eat or it'll get cold."
This time the Stellar Spirit Mage frowned and turned around to see Natsu staring at her. "What? Have I got something on my face?"
Later she swore she didn't know what happened. One moment Natsu was in bed, sleepy and adorable, and the next he was standing over her, much too close and seeming taller than before. "N-Natsu?" Lucy's heart stuttered as she felt a burning hand under her chin, gently tilting her head back and Natsu was there, peering at her with those dark, dark eyes.
"Lucy? When did you get so pretty?" A warm thumb grazed her lips and Lucy flushed crimson. Slowly Natsu stroked his thumb over her lips again and Lucy could have sworn he drew a little closer. Heat was pouring off of him and now he was merely centimetres away. "Hmm? Lucy?" The sound of his deep, rough voice was enough to snap Lucy out of her daze and with a little squeak she pushed Natsu over. "I-idiot! Do you have a fever or something?"
The idiot in question was lying back on his bed, face slightly flushed, and as she stood over him Natsu beamed at the blonde. "Nah, you just suddenly look so pretty."

Lucy was worried. After eating and… that Natsu had passed outand now he was, quite literally, burning up. His bed had long since disintegrated so Lucy had, wearing oven mitts of course, rolled him into the bath tub.

The ceramic had started melting.

11:10 am 3 hours

"Natsu! Natsu! Wake up!" Mira poured a bucket of icy water, courtesy of Gray, over the unconscious Natsu. When the ceramic had started bubbling Lucy had run down to the guild and fetched Mira: the resident Mum, Gazille: encase he had a weird dragon disease, Grey: ice vendor extraordinaire and Levy: honorary genius. Natsu growled when the bucket of water crashed down on him but all the four got for their troubles was a lot of steam.
"Gazille! Do you know what's the matter with him?"
The Iron Dragon Slayer grinned. "Karma."

The other mages had quickly gathered around Gazille, though Gray tried to look disinterested as he filled the tub with ice. Lucy poked the Iron Dragon Slayer. "What do you mean karma? What's the matter with him? How do we fix it?"
Gazille glared at her and rubbed his chest. "Serves the bastard right. Growing pains. Wait twenty four hours and he'll be fine."
The assembled friends' jaws dropped with the penny. "Y-you don't mean… that." Lucy gaped at Gazille, her expression horrified. "Not… that."
"Ha! Your 'Likkle Natsu' is growing up!"

He was still laughing as he was forcibly ejected from Natsu's home.

12:02 am; 4 hours

Mira and Lucy sat at the bar, plotting. Fortunately most people were out on jobs today or, in a certain special case, fishing. Levy was chattering away at Gazille who was pretending not to be interested, but they were about it. Lucy wailed. "Miraaa! Most of his apartment is wrecked!"
There was a giggle. "Well, it's still standing, Lucy. I reckon we got lucky."
"What are we going to do?"
"Well, like Gazille said, we're just going to have to wait till he's recovered. Gray's gone to dump him in a lake and keep him cool, so I doubt Magnolia or the guild will be harmed."
Lucy sighed and rested her chin on her hands. "I wonder what he'll be like now he's changing." The blonde sighed. She wasn't sure she was happy Natsu was growing. They'd been the perfect team for nearly a year now and the thought of Natsu acting like an adult was… strange. Would he still be friends with her afterwards? Or would he start chasing civilian girls, like Loki did?
"He'll still be a moron."
Lucy glanced over at Gazille, who rolled his eyes at her stupefied expression. "Don't look like your cat just got run over. He'll still be that retard. A bit taller, a bit stronger and getting the point of boobs, but he'll still be Natsu."
Levy piped in, "I'm sure he'll be fine Lu! Though it's sweet that you're so worried!"

4:09 pm; 7 hours

A young boy… no man now, gasped as steam rolled around him. He was barely conscious, though the cool water felt good upon his burning skin. He hadn't been in this much pain in a long time.

How had he not noticed how pretty she was?

6:12 pm; 9 hours

Lucy was worried. So, so worried. Sure, Gazille said that Natsu would be fine in a day but it wasn't like they had a reservoir of knowledge to draw upon. All they had was the reassurance of one Dragon Slayer. Gazille said that Metalicana had told him what would happen before he'd disappeared and that was a little more reassuring, but when it was your best friend… Lucy tried to stop fretting and focus on her book. It was utterly futile.

Why was it that all she could think about was the feeling of searing heat brushing her lips? Lucy closed her eyes and sighed. For a second she'd thought he was going to kiss her and, just for a second, ...she'd wanted him too.

7:01 pm; 10 hours

Gray had taken Natsu to the lake where Happy had been fishing and now the little cat was flying back and forth in a general panic. Mira had appointed him as chief messenger to try to get him to stop fretting and Happy was taking his job very seriously.
"General Mirajane! Private Gray has requested that someone cover the next seven hours! He claims he has very little magic power left and that Natsu's temperature, though still high, is more stable. He is in the process of transporting him back to the bathtub but feels he needs some sleep before he can continue."
Levy jumped in. "Gazille and I will take the next seven hours!"
"We will?"
"Yes! I can fire cold words at him if necessary and you can make the place fireproof. It's perfect!"
Gazille grumbled but didn't put up any resistance as Levy led him away. Mirajane smiled at Lucy. "It looks like my matchmaking skills aren't needed after all."
Lucy blinked as she tried to work this one out. "…You want Levy and Gazille together?"
"Of course! I've worked out pairings for everyone in the guild! Fortunately those two look like they don't need my help!"
Lucy's expression was slightly panicky. "E-everyone?"
"Yup! It's my dream for everyone to find the happiness of love!" Mirajane was utterly shameless using that cheesy line.
"Ugh, I don't even want to know who you want me with."
"Hee, well, my hope for you two has now been rejuvenated."
Lucy blushed. "So subtle, Mira. Anyway. I'll take the two to nine in the morning shift once Levy and Gazille are finished."
"Aw, so you want to be there when he wakes up?"
"S-shut up!"

2:00 am; 17 hours

Lucy had gone straight to bed after her talk with Mira. She was determined not to fall asleep whilst watching over Natsu. Her friend was in trouble and she would be there for him. So now she was sitting in his bathroom, absentmindedly running her fingers through his damp pink hair. Lucy smiled, so Mira had been right about Levy and Gazille, had she? Though Lucy had no evidence Levy's grin and Gazille's slightly pink cheeks had been a definite hint. Mirajane certainly had a talent with these things. Lucy almost laughed before a thought struck her. Mira wanted her and Natsu together. Her fingers slowed as the blonde thought about this. It was true that she'd been wondering what it'd be like to have a boyfriend and maybe deep down, when she was half drunk with exhaustion, she imagined what it'd be like if that boyfriend had pink hair. But then he'd do something stupid and the little niggling curiosity was ruthlessly trampled. …But he was going to be properly eighteen when he woke up. Would he really still be her loud, crazy Natsu? And even if he was… would he want her like that. Lucy sighed and resumed petting his pink hair; there wasn't much point fretting about it, was there?

Lucy rested her chin on her hands and wondered what it'd be like to kiss him.

Someone was stroking his hair. The pain was starting to fade from his fingertips and this new sensation was quite, quite wonderful.

Natsu shifted in his sleep and wondered what it'd be like to kiss her.

8 am; 24 hours

Lucy stared at the clock she'd brought over with her, feeling uncomfortably like a zombie. She hadn't slept since two in the morning and all Natsu had done was sit in a bathtub full of evaporating water like a vegetable.
The girl's eyes snapped back to his unconscious form only to see him propped up on one elbow and blinking blearily at her; bed hair smoothed down from his soaking. "NATSU! YOU'RE ALIVE!"
All thoughts of being careful around the newly awakened Dragon Slayer dissolved in the wake of Lucy's overwhelming, painful relief. As she threw her arms around him Lucy didn't care that she was soaked, she didn't care that Natsu was laughing, she didn't care about a damned thing. Natsu was alright and that was all that mattered.

As a pair of strong warm arms wrapped around her waist and gently tugged her into the bath, the rough laughter still ringing in her ears, Lucy found herself sitting in the warm water, drenched through and enveloped in Natsu's warm embrace. The blonde mage shivered as he murmured in her ear. "I had a dream about you."

And Lucy decided that she wouldn't mind a kiss or two.

All finished! I hope you enjoyed. 3 I love, love, love this pairing, so feel free to use the idea or right the second part of the story if you want to! Just credit me and then send me the link! I want to read them too! Please review so I can see what to improve on and if you like leave suggestions for another NaLu one shot! Once again: Sorry for the awkward writing style!