Nezuko got up early morning as she finally puts on the Demon Slayer uniform she had received from the Final Selection. 

She never thought it would be even possible that she would received her first mission as a Demon Slayer right after she received her black sword. 

Although she felt kind of relieved at some point that her reality of becoming a Demon Slayer would come true. 

"Well, I guess there is no point of going back now." She thought in her mind as her sensei asked her, "Nezuko, you done changing?"

She turns around to have the official uniform over her family hakoi , which she decided to wear for now on, to remind her of her family that she had left behind. 

"Do I look bad, Sensei?" She asks nervously of his option, as the man smiles behind his mask, "No, Nezuko. I think you looked absolutely stunning with that uniform. It suits you." 

Nezuko blushed at her sensei's words. 

Nezuko smiles as she sat down . 

"Your uniform is special, Nezuko. It would help you breathe better than before. Also, there is something you should be aware of. 

You remember how I said that nobody has a black sword as a Demon Slayer?"

"Yeah, you did mention that, Sensei. Why is that?" She ask. 

"Well, to be honest, we Demon Slayers doesn't know anything about them. You're the only one I've known to have this type of sword to begin with." Her sensei replied. 

Nezuko blinks in pure amazement, as she looks at her brand-new sword, as it truly is a mystery that the Demon Slayers themselves never know the truth about them. 

Neither of them spoke for a while, but then her sensei reveals something to Nezuko, a brown box, almost similar of what Nezuko had been using to carry her brother to the mountain. 

"I made this box for you. It will be a big help to you, to carry your brother in daylight. " He said, which makes Nezuko felt happy that she has something for her brother to be in. 

Nezuko seems to be eager to hit the road towards the town she needed to be in, as she bows her sensei in respect of his teachings. 

"Sensei, I.. I'm grateful of all the things you taught me since I arrived here. And I'm also grateful that you watched over Tanjiro while I was away for the Final Selection. 

I hoped that he wasn't a bother to you." 

Her sensei said, waving, "It's nothing that couldn't be handled, my dear. I think it's best that you hit the road now. " 

Nezuko nods, concurring with her sensei, "I guess you're right about that." 

She headed towards her brother's bedroom, as the demon boy was still in his covers. 

Nezuko opens the box, as she asks, "Tanjiro? Can you come inside this box? You'll be more comfortable in here." 

The boy went inside the box as his sister suggested as Nezuko beams at the demon boy, "It's going to be fine, Tanjiro. 

It's going to be us from now on. " 

She left her sensei's home as she walks through the grasslands, alone, with her brother by her side. 

When she arrived at the town, she sniffs the town, to inspect it. As it turns out her Crow was telling her the truth. 

"He wasn't joking. I can smell the blood of the missing girls. This could be messy." She thought in her mind.

A boy notices her uniform, "Hey! You're a Demon Slayer, aren't you? Please help me find my bride to be, Satoko. " 

She knew that the Demon would come out only when it is at night. "All right, I will help, what's your name?"

The boy replied, "My name is Kazumi." 

"Kazumi, I think I have an idea of where Ms. Satoko might be. Stay very close to me and do exactly as I say." 

Kazumi nods at Nezuko's words to hoping that they will find Satoko. Nezuko knew that things would be worse if Satoko was eaten, it will break her husband to find her dead, just like she had experience it for herself, of finding out that her family , besides Tanjiro was dead on her doorstep. 

Kazumi and Nezuko waited for the village to go dark. He showed her of where Satoko was last seen. 

"This is the archway that we used to walk together. She was with me for one second, the next thing I knew she was gone. 

Am I going crazy?" He asks her, because no one in the village believed him. 

"You're not crazy, Kazumi. This is a work of a demon . I'm sure of it." She replied to him, as she sniffed the air , as to her amazement, she located the demon right away. 

Kazumi ran after her as he thought in amazed expression of how fast she was going. 

"Whoa, this girl , she's extremely fast! I never seen anything like it before." He thought as he finally caught up to the Demon Slayer. 

She sniffed out the demon as Nezuko thought, "So, a demon holding a girl hostage, huh? Well, not for long!" 

She stabs the hole where the demon was hiding underground as Nezuko jumps into pure action as she grabs the hostage girl, who was unconscious from the demon. 

The demon appears as Nezuko gasps of what type of opponent she was actually facing against. 

"Another morphed demon? You got to be kidding me." She said, holding the girl, as she groans of facing another morphed demon just like in the Final Selection .

She turns to Kazumi, "Kazumi, can I ask you for a quick favor? Watch over this girl for me while I fight this demon." 

"Uh... sure thing." He said as Nezuko hands the girl over to him.

Nezuko still holds her black sword, as she thought, "This demon can appear anywhere. Where in the heck he go?"

She looks down as she saw there were multiplying. 

"Multiply demons?!? Great, that's the least of my worries.  Eight Form! Water Breathing, Water Basin!" 

She thought back of her conversation she had with her sensei before leaving his home, "Nezuko, there is something I want to discuss with you." 

"What is it, Sensei?" 

"There is a person who might know how to transform your brother back into a human. His name is Muzan Kibutsuji." 

It brought her great desire to find this person no matter what. She knew that Muzan Kibutsuji was the key of solving the mystery of restoring her brother's human form.

The attack was brutal as it cuts the demon's arms out in thin air. 

The demon disappears again, but Nezuko was determined to finish him. She backs up of Kazumi and the girl from being hurt in the process. 

"Second Form, Water Wheel!" She thought as she makes the move, but unfortunately, she wasn't able to slice the demon head on.

"Where is Satoko?" Kazumi yells at the demon. 

The demon said, "Well, I have devoured her, just like the other girls. See, this is her hairpin right here." 

Kazumi cries of seeing his dead girl's hairpin as Nezuko seems to know the feeling too well of loosing someone you love. 

Nezuko snaps at the demon, for showing him the pain she has experienced, as she dashed forward. 

But the demon doged the attack as she thought, "I have missed again! What can I do to stop him from going to different places at this rate?"

The demon was about to attack her, but with a sudden shock, Tanjiro came out of the box, protecting the Demon Slayer, by kicking the demon out of his sister's way!

The demon said, "A demon traveling with a human?!? How is that even possible?!? He should've devoured her like us!" 

Tanjiro approaches Kazumi and the unconious girl as he had envisions them as they were his family members who were scared. 

Tanjiro faces the demon as Nezuko remembers what her sensei had told her. 

"While you were away, Tanjiro was still asleep. I put a hypnotic suggestion on him, as if he had a will of his own." 

" Protect the humans. They are your family. The demons are the enemy! " 

Tanjiro snaps in control as he launches an attack on the demon! 

"Wait, Tanjiro!" Nezuko said, of worrying about her brother attacking the demon head on, as Sakonji continues, "Never forgive any demon who harms a human against their will!" 

Nezuko never seen her brother act this way. "Tanjiro." She said watching her demon brother in pure worry.