Author's Note: Hiii its me again! I'm back after a while with a new story! This one's based Demon Slayer Kimetsu No Yaiba. I recently got into the series and I fell in love with it. But I noticed there were NO sickfics of it on here. So to my disappointment I thought, okay time to take matters into my own hands here! And after a few months of thinking, I got this interesting idea. And I'm aware that the manga confirms that demons can't get sick, but hey Nezuko's a unique demon so maybe she's an exception) It'll be a bit more intense than my usual fluffy fics, this one has a bit of a story arc to it. As usual I hope you enjoy and I hope I do these characters justice or get their personalities right in the writing because I've only been into this series for a couple months.

This may also be my longest fic yet. I have some plans for this one c:

Chapter 5: Tanjiro, sleepless and worried cares for Nezuko on his own the best that he can.

Just as Tanjiro thought, Inosuke soon let Nezuko go as he went back into the weird position he was always in as he slept. Tanjiro continued what Inosuke started picking Nezuko up and cradling her softly as she moaned in her restless sleep. Zenitsu sat beside him watching over her as well until sleep eventually took him too. Leaving a sleepless Tanjiro to care for his sister, alone in the night.

He tried holding her close to him as Insouke did with his arms trying to warm her up. Nezuko slightly squirmed in the blanket, clearly, she was uncomfortable due to the fever. But her movements were soft and delicate, she looked just like a fussing baby in her brother's arms.

Tanjiro looked down at her looking worried yet caring.

"It'll be okay Nezuko. Once morning comes, we're going to try to find a way to get you better…I promise." Tanjiro whispered softy.

Nezuko didn't respond and remained quiet aside of her heavy breathing patterns. Her shivering was settled down a bit by the blanket wrap she was in. Then she moaned and looked uncomfortable again. Tanjiro looked over at his two friends snoring in their futons. Maybe this loud noise was bringing his sister discomfort.

Tanjiro stood up slowly trying to not startle Nezuko in the process and then he walked over to the door leading outside the room. He slid it open quietly walking out and sliding it closed to not wake up his friends. It had stopped raining, but it still felt humid and cold. Tanjiro didn't mind and thought maybe the cool moist air would soothe his sister's burning temperature. He then sat down still holding his wrapped sister close to him. She seemed to be a bit more stable after she was taken away from the loud noises in the other room. Her breathing was still heavy, but she didn't look as bad as she did before. The blanket restraint trick really worked.

"It sure is nice out here… The rain stopped, and the damp breeze feels kinda good huh?"

Nezuko moaned slightly.

"I'm sorry I can't do anything to make the pain go away…" Tanjiro began tearing up. "I'm sorry that you're like this…if you weren't a demon, maybe your fever wouldn't be this high and hurt you this much…"

He moved his forehead down to touch hers with his eye closed.

"I'm not going to lose you to this…I swear it. You have to keep fighting and hanging in there…"

The warm tears began to slide down Tanjiro's cheeks and hit Nezuko's cheeks.

"I swear I'll cure you from this…and then I'll make you human again…"

Tanjiro was starting to lose consciousness due to being tired. He started slipping away into sleep with his eyes still shut and his head still against his sister's. The warmth from her fever felt good in the cold air making Tanjiro drowsy. But then he heard a voice come out of nowhere.

"It…hurts…"

Tanjiro then woke up. But he was no longer outside the inn. He found himself now standing in a voided room. There was nothing in sight and it was dark. What was he doing just now? He remembered he heard a voice. Where did it come from? Tanjiro's ears weren't like Zenitsu's but he still focused and tried to find the source of the voice. He was quite sure it was the voice of a young girl. Was someone in trouble? He moved around trying to continue listening for the voice again. He couldn't quite make out who was speaking, the voice sounded distorted at first, but he could still make out the words but not the tone of voice. But it sounded like a girl or a child speaking.

He moved in to see a red light in the distance. He followed it by running. The path seemed endless. The voice got more and more clear. Repeatedly saying "It hurts" Tanjiro continued listening and then his eyes grew wide.

This voice

There's no mistaking it!

It was Nezuko!

It wasn't even that long since she became a demon. Only 2 years. Had he really forgotten what his own sister's voice sounded like? He did remember thinking of hearing her once before while she was sleeping but he was sure it was his imagination. He began running faster following his sister's voice.

Then after some time, he came across a red cage that looked as if it was glowing. The cage resembled thorny vines surrounding something in their center. Tanjiro wanted to destroy the vines to move past the obstacle, but he didn't have his blade with him. He looked over and found his sister enveloped by the vines. As if she was trapped by them.

Tanjiro placed his hand on the vines, but they were scorching hot. He winced pulling his hands back. He tried calling out to her.

"Nezuko!"

She didn't respond or head him. It was like Tanjiro's existence wasn't even there to begin with. No matter how much he called, he didn't get a single reaction from her.

All he could do was watch as she muttered things under her breath. She wasn't muzzled in this form. And she wasn't little either. She was her normal human size speaking like her normal human self. But she was still a demon here, evidence by the claws that were attached to her hands as she held her knees with her face buried within them. She had no clothes on and her long black hair was floating all around her as if she were a spirit. She began speaking again, softly, and slowly. It was barely audible but because it was so quiet there, Tanjiro heard every word.

"It…hurts…"

"It's…hot…"

"I'm…scared…"

"Big…brother…"

"Where…are you…"

Tanjiro then woke up, sitting down at the porch of the inn once again lifting his head and looking down seeing Nezuko's face. She was just as she was left, wrapped in the blanket and in his arms. Had he fallen asleep? Luckily, it was still dark out so Nezuko wasn't in any danger. But he took one look at Nezuko and she looked like she was in pain. She was moaning and her eyes were clenched. Tanjiro wondered where that was that he came from. But then after some time, he put the pieces together.

He was in Nezuko's mind. Everything about that place was too surreal to be legit. It even felt different. He concluded that the bare Nezuko in the cage of that voided area was representing Nezuko's subconscious. And the heated cage was a perception of the illness. She felt scared, trapped and the prison was also heated. All of these things were Nezuko's way of trying to figure out what was wrong with her. Her perception of the illness. She was a demon, so her memory was probably completely reset after she changed. Meaning she had no idea what being sick was like anymore, so she had no idea what was going on. And was probably scared and confused.

Tanjiro looked down at his sister frowning and then remembered what Nezuko said in her spoken thoughts before he woke back up again.

She had called for him.

She wanted him.

He was someone who brought her comfort.

Since she became a demon, he was the only person she wanted to protect and felt she could trust. So of course, she'd want someone like that during this scary time. Because the memory of the rest of their family…had otherwise been erased.

Tanjiro's heart broke thinking all of this as he held his sister close to him trying to comfort her in her panicked state. Responding to her call hoping she'd hear him.

"I'm right here Nezuko. I'm here. I'm not leaving your side…"

Chapter 5 is done!