After a strange meeting with Kamado Tanjiro, Agatsuma Zenitsu and Hashibira Inosuke, Goku parted ways with them, in order to continue his journey.
"Those guys... I hope I'll them again any soon..." whispered Goku to himself. Suddenly, Rin arrived once again, placing on Goku's shoulder.
"Caw! New mission! No time to rest! Caw!" She said.
"What is it, Rin?" Asked Goku.
"A very powerful demon is heading for Ragako village, you have to hurry! Caw!" Said Rin.
"Ragako, you said? That's the village I used to visit three years ago..." said Goku, realizing, "I have to hurry!"
And so, Goku ran faster than he could.
(Ragako... I thought it'd been destroyed... Hiroshi-san, I hope you're safe...) hoped Goku in his mind, (It's a shame I can't have a minute to rest though... I just faced Kyogai a few hours ago, and now this one...)
Finally, Goku arrived to Ragako, where he found the village still intact.
"Fine... I arrived before the demon..." said Goku, calming down. As he walked towards the village, he felt like home once again.
Suddenly, a voice.
"Is that really you... Goku?"
The voice was Hiroshi's.
"Hiroshi-san!" Exclaimed Goku. "You're safe!"
"I am," said Hiroshi, "you've grown up a lot... What brings you here?"
"A demon who's coming here..." replied Goku, "a very strong one, moreover..."
"I have to ask you one thing, Hiroshi-san. Once the fight starts, hide. You and the rest of the villagers, hide. I don't want any of you to die today. Can you do it?"
"I can, Goku," answered Hiroshi.
"Fine," said Goku, "do it, then."
Goku walked around the village in searched of the demon.
(If what Rin said is true, this demon is not like the others I've fought until now...) he thought.
Suddenly, while he was on the rooftop of a house, Goku heard something behind him. he turned. He saw a girl, rising on the rooftop. The girl had white skin, hair, and horns. She had red lines under her eyes, which were red as well.
"Who are you?" Asked Goku.
"Are you a Hashira?" asked the girl.
"I'm not a Hashira," replied Goku, "why are you asking?"
"Oh, that's fine..." said the girl, "you know, I'm afraid of the Hashiras... as for answering your question, I'm Mukago."
"Judging on your appearance, you're a demon, aren't you?" hypothesyzed Goku.
"I... I am," replied Mukago, "but I don't like fighting, especially the Hashiras..."
"So... Why did you come here?" Asked Goku.
"Because... He ordered me to do so," said Mukago, "I don't like fighting, but if I don't obey to him, he'll kill me..."
"When you say 'him,' are you talking about Muzan?" asked Goku. Mukago nodded.
"Oh, I see... I understand you, Mukago. I really dislike fighting girls, so I have to ask you to leave without fighting..." said Goku, but his grip was already on his katana.
"I would, but if I do, he'll kill me..." said Mukago, "even now, he's watching me..."
"Oh, I see," sighed Goku, "guess I have to one-shot you, then..."
The boy took his katana and attacked Mukago, but suddenly, Mukago raised her arm, and from the rooftop, a massive plant emerged, forcing Goku to jump backwards.
(She wants to fight... Understandable,) he thought, (Hiroshi-san and the others already hid... This means I can go all out here, without risking anyone's life...)
"Flame Breathing: Fourth Form -- Blooming Flame Undulation!"
In a fraction of second, Goku rushed forth towards Mukago. However, Mukago jumped high and dodged.
"I knew it!" exclaimed Goku. The boy jumped higher, reaching Mukago.
"Fifth Form -- Fire Tiger!" He exclaimed. Goku rushed towards Mukago in a nosedive. This time, the attack landed, and both of them crushed against the rooftop of the house for the impact.
(Ugh... He's strong...) thought Mukago, "Blood Demon Art: Growing Plants!"
Fortunately, Goku jumped and dodged, avoiding to being impaled by Mukago's massive spear-shaped plant. He then jumped outside the house, wiping his face.
(She almost got me...) he thought. Suddenly, from the floor, a lot of spear-shaped plants started to rise from the floor. Goku kept jumping to dodge, but the plants kept rising. Eventually, Goku got stabbed on the right shoulder by a plant.
(Damnation... She got me...) he said, narrowing his face in pain, "Third Form -- Blazing Universe!"
The plants got cut clean off.
"Where is she...?" muttered Goku.
"Right here," said Mukago, reappearing in front of him and kicking his stomach. Goku spat blood.
"Ugh!" he coughed, (At this rate, I'm gonna die for sure...)
"Before killing you, I want to tell you this:" said Mukago, "I'm a Lower Moon. The Four, for being exact."
"Lower Moon? What is it?" Asked Goku, clutching his shoulder.
The Lower Moons are part of the Twelve Kizuki, the twelve strongest demons who serves him. In my case, I'm Lower Moon Four, so I'm the fourth strongest Lower Moon. Upper Moons are stronger than Lower Moons," explained Mukago.
"Oh, I see..." said Goku, (I'm injured, I'm bleeding, I can barely stand... But I can't give up... I have to fight...!)
(What if.... What if I use Sun Breathing now? It's risky, I know, but... It's the only chance I've got if I want to survive...) thought Goku. Actually, nobody was watching, and Goku was on the verge of the death. The only reasonable solution was indeed Sun Breathing.
(Okay... Just this time...)
With his feet, the boy digged firmly on the floor.
"Sun Breathing: First Form -- Dance!" Exclaimed Goku. Mukago took the hit, and she stumbled backwards several feets away.
(What... what was that... It wasn't Flame Breathing...) shethought, (He's... He's a Sun Breathing user!)
"I have to tell him!" screamed Mukago, starting to retreat. As she started run towards the forest to escape, Goku followed her. He knew: If she were to say Muzan about his Sun Breathing, everything would have been useless.
"You're not getting away!" He exclaimed, launching towards Mukago, "Second Form -- Clear Blue Sky!"
Goku's blade collided with Mukago's neck.
(He's going to cut me... I can't allow it, I'm one of the Twelve Kizuki...) thought Mukago. Then, with a last effort and struggle, Goku finally beheaded Mukago.
(I... I won... I really killed her...) realized Goku. Mukago's head fell on the floor, and her body fell motionless.
"Since I can't tell him anymore, please, tell me... Was it Sun Breathing?" Asked Mukago, while her head slowly began to fade.
"It was," replied Goku, "though I'm not telling you how I'm able to use it."
"I... I see..." said Mukago, "thank you, slayer... You finally freed me from this infinite cycle of fights... Thank you..."
Her eyes wells up with tears.
"I hope you reach Jannah," said Goku, sheathing his sword inside its custody. Eventually, Mukago's head faded away, and every trace of her disappeared.
When Mukago's head finished to fade, Goku turned back and reached the forest, where Hiroshi and the others were hiding.
"Ugh... My wounds hurts..." said Goku, stopping in mid-walk and kneeling on the floor, "ugh..."
Fortunately, Hiroshi arrived.
"Goku! How are you? Where's the demon?" He asked, rushing to his side.
"Eheh, I killed her..." muttered Goku, smiling and coughing again, "but now, I think I need a doctor..."
Then, Goku slowly closed his eyes and passed out.
"You fought well, Goku..." said Hiroshi, taking Goku on his shoulders and carrying him inside his house. For the first time, Goku used Sun Breathing against an opponent. Fortunately, nobody saw him. Furthermore, he also managed to do something every demon slayer dreamed of: Killing one of the Twelve Kizuki.
Chapter 7 - End.