Disclaimer: Natsume Yuujinchou and its characters are not my property, and I am not profiting in any way from this story.

Author's Note: Just a 'what-if' thought I had after the mermaid story.

Forever

By Sinnatious

"...Natsume?"

The sandy-haired boy paused, eyes already searching the street, seeking hidden spirits. The large cat sniffed the air, but didn't otherwise react to the summons. There was no danger – he'd have sensed it long before they were in calling distance.

"Is it really you? Natsume Takashi?"

Not a spirit in sight. Slowly, light brown eyes turned to the elderly man standing on the corner. Bald head. Glasses. Wrinkles settling in for permanent residency around the mouth and eyes.

"Mr Tanuma?" He asked, bewildered. "But that's not possible…" His eyes widened, at the same moment Madara finally identified the familiar scent. "Tanuma Kaname?"

He must have been at least sixty years old, though Madara never counted properly and Natsume had stopped telling him.

"Sensei, will you be lonely when I die?"

"It is you. At first I thought my eyes were playing tricks on me… just like they used to." A brief chuckle. "You shouldn't surprise me like that. I'm not as resilient to shock as I used to be."

"I'm sor-" The apology half-slipped from his companion's lips, and Madara huffed to himself, half from fondness, half from annoyance.

"No, no. Our first meeting after so long – do you have some time? This probably isn't a conversation for the street. My house isn't far. I'll make us tea." Tanuma was far pushier than the spirit cat remembered him being, but people changed. He turned and took a few steps, before looking back to make sure his old friend was following.

His quiet certainty that they would follow was powerful enough to stay the standard flight response and keep them trailing him in an uneasy silence back to his house, though Natsume fidgeted and gazed longingly down the side streets. He was never given the opportunity to escape, as they walked only a scant three blocks before coming to a traditional house with a small yard, nestled snugly between modern apartment complexes and convenience stores.

"Don't say such creepy things. I'm looking forward to it. The Book of Friends will finally be mine!"

"You'll have to forgive me for not knowing how to really react. I heard the rumours, but it's a little shocking," Tanuma apologised as he set out some tea for them inside. "Oh, Ponta is still with you?" A weathered hand caressed his white fur gently.

Tanuma didn't notice the pale fingers tightening around Natsume's knees, but Madara did. "Yes." He didn't elaborate.

"I'm not good at goodbyes like you are, sensei."

"…Will you explain it to me?"

Natsume jolted, glancing up and meeting his old friend's eyes properly for the first time. "Explain?"

Tanuma just smiled softly – the same expression his father bore whenever they'd requested something of the monk. He wore it well. "I understand if you don't want to. But even if I can't see as well as you, I can see enough to believe anything you'll say."

Madara curled up on the provided cushion, keeping one lazy eye on the proceedings. He had no place in human affairs – the only human affair for quite a while. He was curious as to how Reiko's grandson would deal with it.

For a time, there was understanding. Natsume Takashi was kind and gentle and naive, after all, nothing like the brash Reiko. Reiko was full of good intentions, but kind wasn't the word most of her many spirit friends would ascribe to her, and certainly no one would accuse her of naiveté.

Old habits died hard, apparently. "It's… nothing."

The smile slipped a little from Tanuma's face, and he looked tired, showing the signs of his age for the first time. "You're still doing that?"

Natsume stared at his knees. The elderly man sighed.

"We were worried. We all wondered where you went. Me and Tooru especially. We had a child, you know. A cute little girl. We wanted to invite you to the naming ceremony, but you'd already vanished by then."

The air in the room grew heavier.

"Couldn't see spirits at all, though. Not even with Tooru's circles." He chuckled. "She did, however, inherit her love of cute things. You're unlucky, Ponta – the two of them are on a hot springs tour at the moment."

Madara sniffed and turned his head away. "Tch! They should show more respect to someone of my level."

Tanuma's smile was tinged with nostalgia – the sort all humans seemed to carry with them as they entered their autumn years. "Well, perhaps it's for the best." His expression grew sombre. "I'm not sure if Tooru could handle the surprise. Our first meeting in forty years… and here you are, looking like you haven't aged a day."

"That old woman passed away, apparently. The one at the inn."

"Who?"

"You don't even remember that? The one the mermaid played a trick on. I nearly drowned!"

"Your own fault. I told you mermaids hate humans."

"She came around in the end, once she got her name back."

"You're a special case."

"I'm still human."

Natsume kept staring at the floor. Tanuma took several sips of his tea, while the second cup grew cold on the table. Madara waited.

"…Have you heard the legend about mermaid's blood?"

A jerk, and a flash of recognition in those dark eyes. Madara wasn't surprised. Natsume might never have noticed, but Tanuma had once upon a time studied spirits extensively in order to be of help, despite his limited senses. The cat guessed it was how he and Taki hit it off. "I've read some folklore about it in Tooru's collection, but had no way of knowing if any of it was true."

"It is," Natsume confirmed, arms hugging his chest self-consciously.

The silence was long and pressing. Neither of the two boys had been chatty in their adolescence, and it appeared that the years had done little to change that.

"…I see. That explains it, then. But why…?"

"It wasn't my decision." There was no hiding the bitterness those words.

"You were tricked?"

Light brown eyes turned in his direction. Madara flicked an ear and turned his attention to a sparrow fluttering through the plum blossoms in the yard. "…Something like that."

He'd been upset at first, betrayal in his eyes when he awoke to the taste of blood his lips.

"Sensei - why...?"

"…Your luck doesn't seem to have gotten any better over the years. We might be able to find something in Tooru's books…"

"You don't need to go to any trouble," Natsume interrupted. Madara's whiskers twitched, but he didn't comment on the throwback to old ways. His charge was still so concerned about being a burden. "Besides, I've been asking a lot of spirits, and…"

And none of them had an answer. The mermaid's gift wasn't something that could be so easily taken away. But Madara knew it had been phrased so that Tanuma would believe that Natsume was close to finding an answer on his own.

Tanuma would look anyway, of course. But by the time he found anything, if he found anything, Madara was sure they'd be long gone.

Even when Natsume finished high school, and then college, and still hadn't changed, his expression was soft. Even when he had to change jobs every five years, had to break ties with his few precious friends, had to move towns so that people wouldn't wonder why the forty-year-old man still looked like a high school student. Even then, Natsume's gaze - still sad, still lonely - remained soft and full of understanding when he glanced at the cat walking by his side.

Things changed when Fujiwara Shigure passed away of old age, and Natsume was forced to watch the funeral from a distance. When Touko caught sight of him, and gasped of curses.

Natsume's eyes were a little colder after that.

"Where are you staying now? Do you need a place?"

"It's fine. My current job comes with board." Another lie – it sounded effortless, after so many years. Madara himself might have been convinced if he didn't already know that they were between jobs at the moment.

"It's been so long, though – can you stay for just a little while? Tooru will want to see you. I'll warn her – it'll be fine."

"Please don't!" Natsume blurted, then hesitated at the force of his words and the startled expression on his old friend's face. "It's… I'd rather she didn't know. She might worry, or do something dangerous. You… have a family. You can't risk becoming mixed up with spirits again."

"But you shouldn't have to bear the burden alone. We want to help." The words were quiet and even and understanding. Madara could hear the years of reflection put into them.

Natsume didn't respond.

A sigh, and a rustle of cloth as Tanuma folded his arms. "…If that's what you want. But please stay at least until dinner. She won't be back until tomorrow – you could even stay the night. There's so much to catch up on. You must have some amazing stories too. Some happy ones, I hope?"

The first hint of a smile glimmered on that soft face. "…A few."

They wandered the countryside, returning names to spirits. The fox cub grew up and had pups of its own, and brought them to meet Natsume. It was the first time Natsume smiled since Shigure's funeral, and for a short while his eyes were soft and warm and full of forgiveness again.

"Good to hear." There was the trill of a bell in the distance. "Oh, the phone. It might be Tooru. Excuse me, just a moment." With the slowness of old age, Tanuma creaked to his feet and headed into the main hall.

It turned out to be only a telemarketer. Tanuma headed back to the living room. "Sorry about that, Natsume…" He trailed off.

The room was empty, plum blossoms littering the floor by the shouji left ajar.

"You sure you don't want to talk to them?"

"They might accept my sight, Nyanko-sensei, but this curse is something else. It isn't something I can hide."

"Hmph! I don't understand humans. It's a gift, not a curse. One that the mermaid gave willingly. You should be honoured."

"If it can't be returned, it's not a gift, Sensei."

"Natsume! Oi, Natsume!" Madara chased the sound of sneakers pounding on the pavement, huffing from his efforts to keep up. That brat… With nothing more than a brief thought, he transformed into his true shape – the majestic white beast that struck fear into the hearts of lesser spirits. Growling, he took off after the human, finally cornering him in a deserted park several blocks from Tanuma's house.

"Natsume. Don't just run off like that," he chided, crouching low to provide a large, white wall to block his escape.

"Tanuma… he's so…" the boy choked.

Madara didn't comment.

"I hate you. I hate you I hate you I hate you!" The human boy sobbed, a fist pounding his side with each heartbroken declaration, but there was no spiritual energy behind the motion. Each thump grew weaker, and then fingers twined in his fur and he slid to the ground, tears still tracking down his ageless features. "Why, Sensei? Why?"

"I don't understand you, Sensei. Now you'll never get the Book of Friends." The words were hollow - spoken a thousand times. And like a thousand times before, Madara did not answer.

Madara curled around the small, weeping form, long white fur providing a warm pillow for the sandy-coloured head.

He wouldn't be like Reiko, who died young and with hundreds of unfulfilled promises. He wouldn't be a simple blink of Madara's eye. Even if he came to hate him, even if he cried himself to sleep every night, even if the loneliness would eat him alive, the spirit didn't care so long as he could keep the small form by his side.

"I hate you," Natsume whispered, eyes sliding shut as exhaustion claimed him.

Madara didn't pay the proclamation any mind.

Humans couldn't turn into evil spirits, after all.