One week later.
In the demon slayer's training ground, Nameless and Rinka are training together.
Nameless knocks out Rinka to the ground once again. "I've won 100 battles straight up against you. Now it's my 101st time."
Rinka says in a tired voice, "I... I am trying my best. It's not my fault..."
"It's not enough. You have to surpass your limits. How are you supposed to fight an upper-rank demon?"
...
"Good morning, Nameless-kun and Kumagami-Chan!"
A sound comes from behind. They turn their heads and see Ai and Chikafusa coming toward them.
Ai waves her right hand towards them. Her hand is covered with bandages.
"Oh, you two. Long time no see. Glad to see you again in the training ground," says Nameless.
Ai carefully looks up at his body and examines his face. Her hunter eyes widened a bit, and she said, "Nameless-kun, you've changed a lot. Last time when I saw you, you had a somewhat skinny appearance, and now you have an athletic physique."
"I just started to train even harder. Nothing special. If I may ask you, why didn't you come to train for an entire week?"
She softly smiles and says, "It's my fault for not coming for training. I was devastated by the disappearance of Hajime-Kun."
Chikafusa immediately says, "That's right! We couldn't focus on any other thing—"
Ai pinches Chikafusa's waist. "I am not done yet, idiot."
She controls her anger and smiles again, "Even though we lost our precious friend, we ought to train and get stronger to save others. This is the rule of our corps. We can't give up so easily. Now I fully understand this rule."
"You're right. We can't give up no matter what," he says.
He thinks to himself, "Anyway, I am going to die at the hands of the upper-rank demon. So, nothing matters to me. I am just born to die."
Ai looks at both of them and smirks, "Since you've become stronger than before. I, Hanako Ai, challenge you both for a 1v2 truel."
... "Huh?!" Their reactions.
Rinka softly says, "Are you sure, Hanako-San?"
"Of course, I am completely sure. Do not hold back. Try to defeat me however you want. I am feeling so excited, so good about it."
Her strikingly long black hair cascades down to her thighs, swaying gracefully in the breeze. She stands poised, observing quietly. Her piercing hunter-purple eyes gleam with anticipation and excitement.
They hold their swords, staring at her in awe. "Alright! We accept the challenge."
They lunge at her simultaneously.
She effortlessly dodges their attacks. Rinka attacks from behind but she deflects it with her wooden sword. Rinka starts overpowering her and Ai struggles to keep up with her immense strength.
"Kumagami-Chan, your strength is amazing! But it doesn't mean you can also surpass me in speed and skills."
.
Nameless suddenly appears in front of her. Her eyes widened in surprise and uncertainty. His wooden sword is just some millimeters away from her eyes.
...
A few moments later.
Both Nameless and Rinka are lying down on the ground. Ai is still standing and exhausted.
"You've fought well, especially Nameless-kun. Now I have to go. I have some other work to do right now. See ya later!"
She leaves them and Chikafusa behind. Chikafusa watches Ai leaving the training ground so early.
He turns his head back to them and tries to wake them up. "Are you alright!?"
They slowly get up and are barely able to stand.
"Oh man, this is a pain in the ass. Winning more than 100 matches in a row just to be beaten up in a 1v2 duel," says Nameless.
"She is so cool and strong. I could barely keep up with her," says Rinka.
"Kumagami-San, you've fought very well. She is just too strong for now. I'm pretty sure you will surpass her soon," says Chikafusa with excitement.
Nameless glares at him and says in a serious tone, "You're using your charm on her, aren't you? Don't dare to get too close to her."
Chikafusa is confused by his response. "What is he trying to say?.."
Nameless takes a deep sigh and asks, "Anyway, do you have any idea about the upper moons? Like how strong are they?"
Chikafusa is shocked by his sudden question. Suddenly, he remembers his death when he was Tanjiro. A shiver runs through his spine as he remembers the upper moons.
"Yeah, I can say that they're extremely strong. Their powers are beyond ours, especially the strongest ones."
"Have you met any upper moon yet?" asks Nameless.
"I've seen lower moons. And we fought the strongest lower moon, Lower Moon 1. He was much stronger than any ordinary demon, and he destroyed the entire mountain with less effort.
Do you know about the bandages on Ai's hand? The Lower Moon 1 gave her a fatal wound on her hand that she couldn't recover even in three years. Upper Moons are way stronger than him, and the strongest upper moons are even much stronger."
"Oh, that makes sense. So, we can do nothing to them for now."
Chikafusa asks in confusion, "But why are you asking about them?"
"Because I am going to defeat an upper moon demon."
"Oh, please be careful. If you want more information regarding the upper moons, I can tell you one person who knows about them very well."
Nameless's eyes widened in surprise and excitement, "Who could it be?"
——————
Some moments later, Chikafusa arrives in a hidden mansion along with Nameless and Rinka. The mansion is invisible, but Chikafusa has some spell tags to enter the mansion.
"Oh man, what place is this?" asks Nameless.
"This is a hidden mansion of Yushiro. He knows everything you want to ask."
Out of nowhere, a cat appears in front of them and leads them to Yushiro.
They entered a mysterious room. Everywhere is the painting of Lady Tamayo.
"Wow! Who is this beautiful lady? Who made these drawings? They look so wonderful," compliments Rinka.
Suddenly, a voice echoed in the room, "Who are you people?"
"Yushiro-San! It's me, Yamamoto Chikafusa."
...
Yushiro appears in front of them. He hasn't aged since the death of Lady Tamayo.
"Tanjiro-kun, it's you."
Chikafusa smiles and says, "Nice to meet you again, Yushiro-San. Sorry to bother you but my friends wanted to ask you about the upper moons."
Yushiro looks at Nameless and Rinka and says, "So you want to know about the upper moons, huh? What do you want to know about them?"
Nameless politely says, "I want to know everything about them. Like how they look and how strong they are."
Yushiro softly smiles despite having a serious personality. He has been waiting for this moment to tell someone about the upper moons and Muzan for a long time.
"Alright! Follow me," commands Yushiro.
They follow him to another room. The room looks dark and gloomy. But there are paintings of some creepy demons hanging on the wall.
"These are the strongest upper moons, the strongest demons of all time. They are the demons who wiped out the entire demon slayer corps of the Taisho Era where the techniques were at their peaks."
*Akaza*
*Douma*
*Kokushibo*
He then points his finger to Muzan's painting. "And this is Muzan Kibutsuji, the progenitor of all the demons. He is the cause of all causes."
"Your paintings are amazing, Yushiro-San. But how do you know about them so much?" asks Nameless.
"Because... I am a demon who watched everything and the fights in the Infinity Castle."
They both are shocked to hear that he's a demon. But instead of being aggressive, they calmed down themselves.
"I see. What should I do if I encounter them?"
Yushiro says in a serious tone, "I hope you won't encounter these demons I've mentioned. But if your luck is bad and you encounter them, I'll recommend you to forfeit immediately. You can fight any other upper moon but them."
"I see."
"One more thing. If you encounter a dark entity with ominous eyes, leave it immediately too. I haven't seen any kind of entity like it, but Lady Tamayo once told me that there is an entity that exists beneath the shadows."
Rinka asks, "But who is Lady Tamayo?!"
"The lady in the portraits is Lady Tamayo. She is the real owner of this mansion. But sadly, she was killed by that bastard Muzan."
He starts explaining everything about her, Muzan, and the upper moons. His voice turns calmer as he glorifies Lady Tamayo.
——————
After leaving the mansion, they return to their hideout.
They remove the spell tags and then the mansion vanishes from their sights.