You packed your things and started to go on a mission he was required to go on. Genya was supposed to go on another mission, but it was in the same direction. You all need up staying at the halfway point run by an old man. Zenitsu offered to carry you since you kept having to rest after a short five hundred feet, which made you feel bad. You were slowing them down, but Tanjiro insisted you come along.

He cracked jokes while Inosuke insisted that they didn't need you and wanted to leave you somewhere. You didn't blame him because you were tired of you. Maybe you would die this time. You were hoping to because living a life like this was not something you wanted. You wanted to know if there was a next life and if you would be healthy in the next life. You were also loved. You liked Tanjiro, but you knew you would never get married or have kids with the guy or anyone. Tanjiro made you happy and made you feel special and happy. You wanted the happiness that he had or, better yet, give it to others like he did.

Once you reached the house, the boys decided to take a bath, and you stayed behind. It wasn't a mixed bath, so you read a book instead.

"Y/n, let's train," Genya said as you looked up from your book.

"You never want to train with me," you said.

"Well, you are strong. Sometimes, let's see how much it will take to make you that strong again," he said as you looked at him terrified.

"Um, how about no, I never Remember anything from it, and I don't want to hurt you. I like being me when I fight, not someone else," you said as you went back to your book. However, he sliced it in half, making you panic.

"Hey!" You said as he lifted his sword at you, and you glared at him.

"I'm not fighting you, Genya!" You said as you left your room, then the house.

"Yes, you are. You want to be strong, so fight me!" He said as he kept getting closer to you and trying to force a rise out of you.

"No!" You said as he smiled.

"Fine," he said as he picked you up, making you scream and fight him. He took you to the bathhouse, and Tanjiro, Inosuke, and Zenitsu were in the bath. He set your back to them, making Zenitsu scream.

"She can't be here!" Zenitsu yelled.

"What are you doing with her?!" Tanjiro asked as you closed your eyes so you wouldn't look at them by accident.

"Fight me, or I'm pushing you on the water!" He threatened

"Are you crazy how do you think I got sick in the first place? Don't you dare, you know I don't handle being pushed into water well!" You said as panic started to set in.

He pushed you a bit, making you push him back.

"Leave her alone!" Tanjiro yelled.

"Fight me, or you are going into the water. Do you understand me? There are three naked guys here, too!" He threatened as you looked at him angrily.

"What is your problem? I'm so sick of you pushing me around! I'm just trying my best to help. I know I'm not strong or anything, but I'm trying my best here. I don't like not remembering fighting, and when I don't, it scares me because it feels like another person is fighting and not me!" You explained as he pushed you again harder.

You pushed him back just as hard, but then your sleeve got caught on fire, making you scream. Out of pure reflex, he pushed you into the water to put the fire out. You started panicking, and you felt a hand grab you and pull you up so you could breathe.

"Are you alright?" Tanjiro asked as he had covered himself up to help you up.

You were panicking and pushed him away as you were trying to calm yourself down.

"What is wrong with you? You cut my book in half, you catch me on fire, then push me in the bath!" You screamed.

"I didn't catch you on fire! You just burst into flames!" He said as you looked at him angrily.

"Oh, so I just caught on fire now, huh? I'm not a fucking demon last time I checked and it's not even sunny! It's dark! I just wanted to relax! I know it seems like I'm lazy, but I have been trying my best to be like all of you, but I can't be! I can't be like any of you!" You screamed as you got out of the water as fast as you could.

"I didn't mean for you to go into the water!" He said.

"Don't touch me! Don't come near me ever again! I hate you! I'm so sick of everyone pushing me around! I'm tired of it!" You screamed as you threw your wet kimono at him, revealing a white one you had been wearing underneath it.

You quickly ran away crying, and they looked at him shocked.

"Scarring her is funny, setting her on fire! Why would she set her on fire?!" Inosuke yelled.

"I didn't do it! I have nothing on me to do something like that. She can fight, but she just doesn't want to!" He said.

"Have you seen her fight? It's like watching Zenitsu flirt with girls. It's terrible," Inosuke pointed out.

"Inosuke!" Zenitsu complained as he laughed.

Tanjiro got out of the path and put his clothes back on, then went to find you.

"Y/n?" He asked as he knocked, but no answer.

He got worried and opened the door and saw you taking off your wet clothes while crying.

"Close the door!" You screamed as he shut the door, and he closed the door.

"I'm so sorry! Can we talk, please?" He asked as you quickly got dressed and looked at him angrily.

"Why? You didn't do it; Genya did!" You said as you were on the verge of having a breakdown.

"I know, but you're stressed, and I am worried you are going to pass out. Can I help you breathe for a second?" He asked as you looked at him, annoyed.

"Just leave me alone for a little bit, please," you said as Genya tried to force himself into your room. You pushed both of them away and ran outside into the forest.

You were trying not to panic, but you were angry, scared, and upset that he didn't listen to you and caught you on fire. You sat down on a log and started crying your eyes out. Then you heard rustling in the woods.

"Hey Y/n?" Tokito asked as he saw Genya and Tanjiro fighting outside your room.

"What are you two doing?" He asked.

"Genya lit Y/n on fire then pushed her into the bath!" Tanjiro said.

"I didn't catch her on fire she did it herself!" He yelled.

"Where is she?" Tokito asked.

"She left. I don't know where she is," Genya said.

"She doesn't have her sword. With how weak she is even with her sword, she will die if a demon is around," he said as he went to go looking for you but heard you screaming.

"Demon!" You screamed as you were grabbed and then thrown into the house.

You hit all three of them, then you slid a bit and grabbed your sword.

"Sorry about that," you said. Tokito got up, and so did the other two.

"We will take care of this. Genya said as Genya was quickly grabbed, and you cut off the demon's arm, then kicked it back into the woods.

"You three stay here, genya. I have a bone to pick with you," you hissed as you ran out.

Tanjiro, Genya, along with Tokito, followed you only for you to quickly kill the demon with ease.

"Y/n, are you alright?" Tanjiro asked as you looked over the demon and kept stabbing it over and over again.

"No," you said. You quickly grabbed Genya by the throat and started choking him.

"Why did you set my sick baby sister on fire?" You asked as he looked at you confused.

"Y/n?!" He asked.

"She's sleeping and doesn't know I'm here. You don't know when to quit even when she told you to stop!" You said as your eyes turned into demon eyes.

"What the fuck are you?!" He yelled as Zenitsu and Inosuke saw your eyes and were shocked.

"My name is not Y/n she's my sister. I died for my sister, I have been keeping her alive since she was ten! Ten! Do you think she was ever strong enough to defeat demons? You think she would still be alive if it weren't for me?!" She hissed.

"Sarah, that's enough," Tokito said.

"No, it's not, I'm sick and tired of you morons not treating her with respect, pushing her around, hurting her as our parents did! Do you know why she's scared of water? It's because she was always sick, so they tried to drown her! She doesn't remember, but I remember all of it! Who do you think killed her parents? Who do you think protected her from them? It was all me!" She yelled as she slammed Genya into the ground. Your eyes turned back to normal, and you fell to your knees.

"Ow! Guys, why are you looking at me like that? Did I pass out again?" You asked as you tried to get up, but then your sister took over.

"Quite I'm talking!" She yelled.

"Now I'm going to kill you!" She said as Tokito stopped your sword.

"Sarah! I chose to keep the secret of your existence because you saved Rengoku, you never once ate a human, and you killed your parents out of self-defense. Stop this now," he said as she sent him flying.

"You don't think this is self-defense! I'm tired of hiding, and I'm tired of helping my sister live when she does nothing but cry and feel sorry for herself because she exists!" She yelled as you dropped the sword.

"Stop it! Tokito, I don't know what's going on! Something is wrong with me. I can't control it!" You panicked as you were fighting whatever was trying to hurt your friends.

"They are my friends! I will never hurt them! Stop it!" You said as your sister took over stronger than ever.

"Friends?! Friends! You get bullied and pushed around by everyone. Your friends feel sorry that you exist in this world! You think they want you around. I don't even want you around anymore because all you want to do is die by a demon! You have no self-worth after all I have done for you! I'll keep you alive and take you somewhere you will be wanted and cared for!" She yelled as you came back and were holding your head in pain.

"Run!" Tanjiro, please run! Tokito, run!" You screamed in agony.

"I'm not leaving you; I promised I wouldn't leave you ever," he said as he put his sword away.

"Everyone leaves or hurts her! You are no exception! She may see you as her baby brother, but I will never see you that way!" Your sister screamed.

"You need to calm down. You are hurting your sister," Tokito said as you both started streaming in pain, and a mark appeared on your arm.

It caught on fire, and you both separated, making everyone terrified but Tokito.

"Fire broke the mark. It wasn't your fault she was dying, Genya," Tokito said as your sister got up and saw your lifeless body lying on the ground.

"No!!!!" Your sister screamed as she went over to you and held you close.

"No, I can fix this; I have to fix this! Y/n! Come on; please don't die; I'm sorry! I didn't mean it. I just wanted you to be happy and for everyone to stop hurting you. You always got hurt because you were sick all the time. It wasn't your fault! If I weren't born, you would have been healthy!" She cried as everyone was speechless.

"Y/n?" Tanjiro asked as your sister held you close to her chest.

"She was dying?" Genya asked.

"You just had to stress her out, didn't you? If she wasn't so stressed, I could have kept her alive longer!" Sarah screamed.

"Sarah, she was getting sicker and sicker. Your powers were only prolonging her life a little. Suppose you didn't keep her in her body. She would have died without you. I'm sorry for your loss," Tokito said as she looked at you heartbroken.

"Our parents hated her. I was the only one who ever loved her. I turned into a demon to save her. It was for nothing! I just wanted her to be happy, but she just wanted to die because she felt so useless. I should have told her about me, but I was worried she would kill herself," she said as she just held you.

"It's okay, you did the best you could," he said.

"I'm going to stay here with her until sunrise. Can you bury her, please? I don't have the heart to live without my sister," she cried, "Stay away all of you! Stay away from my sister!"

Tanjiro went next to your sister, and she looked at him angrily but then sadly. You were so pale, and no one could believe you just died like that, but then you couched, and you had an extremely high fever.

"Oh my gosh! Y/n!" Your sister yelled.

"Is everyone okay?" You asked, not knowing what's going on.

"Yeah, everyone is fine, don't worry about them, okay?" Sarah cried as she touched her face.

"Can you protect them for me? A demon is out there. Something happened to me, and I don't feel great. It came out of nowhere... I just wanted to be alone for a second," you said weakly.

"Yeah, I will do whatever you want me to do for the rest of your life if you live for me, okay?" She said as she picked you up.

"Tanjiro was trying to stop me from leaving, but I got mad. I think he hates me now," you said.

"Oh baby, he doesn't hate you. No one hates you. I'll take good care of you, okay? I will do my best to make you healthy like I have always done, and I will make sure no one hurts you again," she said as she growled at Genya and Inosuke.

"I need to talk to all of you," Tokito said as they all were confused and scared about what was going on.