The Demon's Sun (Kyojuro Rengoku x OC)

Chapter 1~

The following night, they brought Rengoku and Tanjiro into the dark room Eri had been staying in. She sat in between both of them and watched over them while they slept to make sure nothing went wrong or happened. She was breathing softly and didn't make any noise when she finally decided to get some fresh air. Her steps were the softest thing Zenitsu had heard. He knew she wasn't a bad person, or demon, everything about her was king, gentle, and soft. But he couldn't shake the feeling that she was hiding something from them, something important.

Eri sat on the ground right beside the door and smiled up at the moon. She loved the moon almost as much as she did the sun. She practically baked in the moonlight whenever she could and could always be seen outside during the night. Whether on a train or just walking, she was never inside during the dark hours. "Maybe... they'll finally be willing... to put an end to me." Her voice was soft and she smiled up at the sky as if talking to someone. She shook her head then laughed lightly at her own words, "I don't know why I said that, why get your hopes up, baby girl? I will see you again, though." She held her hand to the sky as if waiting for someone to reach down and grab it. When no one one did she clenched it into a fist and smiled even brighter. "Sister's coming, Aiko." She stood back up and walked into the room once again, checking up on the boys.

Once morning came, Rengoku was the first to wake. He could feel the slight pain in his ribs, but sat up anyways. He looked around for Eri, and spotted her in a dark corner. It looked like she was sleeping, her head propped up against the wall with her knees pulled close to her chest. He flinched at the pain as he tried to stand, and it woke Eri up.

"Hey, stop! You're just going to make it worse." She warned and quickly made him lay back down. "Don't start pushing yourself, you could have easily died out there."

He smiled, "I'm not that fragile."

"I'm not saying you are, but even with a trained body, these injuries have to hurt. Besides, if you move to much, the bleeding will start again and that could be deadly by itself." Her reasoning sounded reasonable so he laid there wondering what compelled her to save him despite his threat of killing her, he didn't know what was actually what she wanted, though.

He looked at her and saw that she was concentrating, so he didn't want to interrupt but his curiosity got the best of him. "Why are you so fixated on helping me?" His eyes shifted away from her to look at the ceiling.

She heard his voice but didn't hear what he had said, when she opened her eyes, he was looking at the ceiling. "Huh? I didn't hear what you said..." she whispered.

"I asked why you were helping me." His voice was simple, but his eyes didn't move an inch. It was intimidating to say the least.

"For multiple reasons. Some which are selfish, while some are pure. Which reasons would you like to hear?" She questioned willing to tell him either.

He hummed and looked at her with a bright smile, "Why not both?" She chuckled.

"Well, frankly, I've been alive for a long time. Everyone I ever love dies. So for my selfish reason, it's because I'm hoping you'll kill me at some point. For the other, though, it's because you're injured, and you showed empathy towards me despite being a demon. You're kind, so why would I let someone like you die when you can be saved? There are to few of people like you as it is..." She explained.

Rengoku looked confused, "Did you not become a demon willingly?" She jumped at his words, but shook her head.

"No, I was forced into. Muzan took my family hostage, and told me if I were to become like him that he'd let them go with their lives. So I did as he wished and became a demon." Rengoku furrowed his eyebrows, it obviously wasn't fair. He thought it was a rough thing to talk about, so he decided to change the subject.