A/N: Hello everyone, Tankana holds my heart right now, and I couldn't help but write this out. For some reason, when it comes to my favorite ships, I LOVE the angsty stuff.

This might have a 2nd chapter… TBD.

Theme: Angst

Timeline: Roughly 5 Years post Muzan's defeat, Tanjiro and Kanao are 21 and married

TW: PTSD

Disclaimer: I do not own these wonderful characters, unfortunately.

Scars

Tanjiro felt the warm, wet tears stream down his face as he stared at his wife. His beautiful wife, so kind, so precious to him, stood in front of him, gripping her sword as she cried and pleaded with him. He wanted to hug her, kiss her, and tell her that it was okay. But instead, he was running to her, with his claws ready to attack.

He couldn't control his body; his movements were not his own. He begged himself to stop, to not inflict harm on the person he loved most in the world. "Stop it, Tanjiro!" He screamed inside his head, but it was no use. He felt his scaly arms grow out from his back, aiming towards the purple-eyed girl in front of him. "No, no, no, no, Muzan, please make it stop!"

"Why would I do that?" The cold voice shouted inside his head. While he did not have a flesh and blood body, the will of the demon king lived on inside the former slayer. Taunting him, driving him to do horrible things. "My blood is your blood. Everyone you kill, everyone who suffers, it's at your hand. I am just watching."

Years ago, he had been turned into a demon. But, Kanao saved him. She put her life on the line to inject medicine that brought him back to the human world. However, Muzan remained in his veins. It was only a matter of time before he took control over him.

Tanjiro sobbed as he took more steps towards her, time standing still but moving too fast. He couldn't stop himself. He felt the drool start to drip from his mouth. He was in dire need of nutrition. But why her? Why couldn't he change the path, or go to sleep? Why couldn't he control himself like his sister could? This was cruel, too cruel.

The gap closed and Kanao fell to her knees. She possessed no medicine, no way to fix it this time. She could not bring her sword down on the man she loved. She accepted her fate to die at his hands.

"No, run, Kanao! Please!" Tanjiro pleaded as he saw her surrender. "Get away from me!"

But she did not run. Time slowed even more as he watched his attack launch towards her, aiming straight for the chest…

"No!"

Tanjiro bolted upright in the bed, sweat dripping off his face as if he had just taken a bath. The moon was bright, shining down on the sweat-drenched bed. Tanjro heaved as his heart raced, trying to get his bearings.

It was a dream.

And it wasn't the first time he had experienced it.

In fact, it was happening night after night. These dreams were plaguing him, and he couldn't shake the feeling that something was going on. They felt so incredibly real, it took him hours to feel back to normal.

He sighed and rolled out of bed, feeling like maybe cleaning the house might help. Even if it was the middle of the night.

He tried to do it as softly as possible so he did not wake his sleeping wife, but she was on edge as well due to his constant nightmares. She stirred as he got out of bed, and Tanjiro couldn't help but stare at her. She was so beautiful. He caressed her cheek as she opened her eyes. "I'm sorry," he whispered, "I didn't mean to wake you."

"Tanjiro," she whispered, her eyes immediately etched with worry. "Another nightmare?"

Tanjiro gave her a small, knowing smile, his face still dripping with sweat. "Yes," he whispered. "It's okay. I'm just going to try to clear my mind a little." He kissed her cheek and squeezed her hand with his good one, before beginning to walk towards the kitchen.

"Anata," she whispered, causing him to pause, "do you want to talk about it?"

As she spoke, she started to stand. The moonlight glistened off of her skin, and Tanjiro caught a glimpse of her scar. That scar. The scar that he inflicted on her.

The process of healing from scaring people he loved took years for him. While Kanao and Nezuko never blamed him for what he did to them, he struggled with forgiving himself. His memories of his short time as a demon were not extensive, however he couldn't help but still feel guilt. Why couldn't he control himself? Why was this the price to pay to survive that battle?

He thought he had healed from it, but the nightmares were bringing it back. And it frustrated him. At the sight of her scar, he winced. And Kanao noticed this.

"Tanjiro," she said again, her voice slightly louder this time. "I'm worried about you."

"I'm fine," is what Tanjiro wanted to say. But he couldn't. Not to his wife, who has stayed by his side through thick and thin, through all the ups and downs, through all of his healing. He was the type to not share when he was having issues, to not be a burden on his sister and friends. He didn't feel like he needed to put that weight on them, when they had their own personal healing. He used to feel this way with Kanao, but this was his wife. She was also extremely good at catching his lying expressions.

No, instead of lying to her, he did the only thing he could think of at that moment. He laid his hand on the scar on her chest, and, inching closer, muttered the words "I'm sorry."

With that, Tanjiro broke down in her arms. "I forgive you, Tanjiro," Kanao whispered as she gently rubbed his back and embraced him. "I always will. It's just a scar."

Tanjiro felt his heart skip a beat. He didn't deserve her. He was broken, so broken, but she was too; and they shared that together.

"I….I," he whispered, trying to get the words out, "I'm so scared of hurting you, still. I keep dreaming that Muzan is still inside me. I can't shake this feeling like he could be invading my brain," he took a deep breath. "I'm so scared."

"Shhh," Kanao sweetly comforted him. "I understand." Kanao did not say anything else as she let her husband release sobs. Tears streamed from her eyes as well. She looked up to him, watching as he broke down. Years ago, she fell in love with him because of his strength, protection and love; but also, his vulnerability with her. She knew that what he needed right now, was just the embrace.

This lasted for several moments before he caught his breath and lifted his head, once again, laying his good hand on her chest, feeling the rough ridge of the scar. She placed her hand over his, leaning in to kiss him on his cheek. He turned his head, planting one on her lips, before they locked and leaned into it together.

For a moment, all of Tanjiro's fears and guilt vanished. It was just him and the woman he loved so dearly. Time stopped as he took in her scent, that sweet, floral scent that he loved so much, and explored her soft lips as much as he could. His hand remained on her scar, as if to associate it with their tender love, and he sighed.

Breaking apart, he pressed his forehead to hers. "I love you, Kanao," he whispered so quietly she almost couldn't hear it.

"I love you too," she said back, before giving him one last peck. Now wrapping her arms around him, she held him tightly, not letting go until he made the action to do so.

He sighed, basking in the comfortable silence. This was something they did well. Tanjiro and Kanao learned many things from one another, and just embracing had quickly become the thing that brought them the most happiness.

Eventually, he chose to break apart from her, and stared into her eyes. Even though he could only see with one eye, he felt Kanao was one hundred times prettier than she was when they met. Her eyes were also damaged. She could not see out of one and barely out of the other. Tanjiro, his right, and Kanao, her left; a match.

"What if…" he trailed off, now looking to the side to hide his emotions. "What if Muzan lives on because I live on?"

Kanao knew the question might come. Afterall, the medicine turned him back into a human; but Tanjiro's body still contained a very large amount of blood from the demon king.

"What if these nightmares aren't just nightmares, but Muzan is somehow still alive and invading my thoughts? What if," he trailed off again, afraid to say it.

"Anata," Kanao slowly spoke, now placing her hand on his head while he avoided her gaze.

"What if," he said again, now meeting her eyes, "as long as I live, so does he?"

There was a pause. Kanao's heart broke. She didn't want Tanjiro to think this way. He was her life, her light, and as far as she felt, the father to her future husband. One year ago, a great relief fell on them when Sanemi and Giyu celebrated their twenty-sixth birthday. They knew that meant that the mark curse was lifted.

But now, a new kind of fear arose in him, realizing that his death could mean the true end of Muzan. Kanao would not take it, though. "Tanjiro, don't think like that," she said, almost sternly. "Even if his blood runs in you, you are human, and he is dead. He cannot come back. He will not come back."

"How can you be so sure?"

"Because of you. Your kindness, strength, and love will keep him at bay. Even if it's true that he lives inside you, he will not survive. Light will always drive out darkness."

Tanjiro paused at this statement. It was exactly what he needed to hear. Afterall, darkness could not overtake a room illuminated by a lantern; but light could always overtake darkness.

He kissed her once more. While he still felt scared, and didn't expect it to go away any time soon, he did feel a little better.

"I'm sorry," he whispered again into her ear.

"Stop apologizing, my love," she said sweetly. "I've told you over and over again to stop. You never need to apologize to me for the things you did in the past. And you don't need to apologize for healing."

"You are amazing, anata," he said, the smile Kanao loved so much flashing on his face. "What did I do to deserve someone like you?"

She smiled back. "I could say the same thing. Who knows where I would be if I never met you."

They hugged once more, shared a final tender kiss, before Kanao made her way back to the bed. "Come try to sleep, Tanjiro," she said, motioning him to come back to bed.

"Okay," he said in response, "but will you stay awake with me, if the nightmares return?"

Kanao's eyes narrowed. He was still clearly scared, and she didn't blame him. "Of course," she whispered, before wrapping herself around him, breathing in his rugged scent.

While they might not have slept a wink before the sun rose, they basked in each other's presence and enjoyed every moment. And Tanjiro knew that if his nightmares came back the next night, he could truly lean on her. And that feeling of darkness inside him that scared him more than he could explain, was starting to be illuminated by light.

A/N: Okaaayyy, I'm really proud of this chapter. I know that Tanjiro seems to be the type of person that can truly handle trauma and move on, but I feel like after EVERYTHING he went through and his tendency to blame himself for things, would lead to something like this.

Hope you all enjoyed it, feel free to leave a review and let me know if you want a chapter 2!