Musashi fell silent, but he had anticipated this situation and already planned what to do if it occurred, so he didn't intend to hide the matter from Zenitsu.
"I've seen him…"
Musashi looked at Zenitsu and said.
"That's good. I thought something might have happened to him. If that were the case, Grandpa would be sad."
Zenitsu felt relieved upon hearing this and said with a smile.
Seeing Zenitsu's relaxed expression, Musashi felt a twinge of pity.
At the same time, he realized from Zenitsu's words that his tolerance for Kaigaku seemed to be largely due to not wanting Kuwajima Jigorō to feel sad or distressed.
Therefore, even though Kaigaku's attitude towards him was extremely harsh, he endured it.
He and Kaigaku were almost polar opposites: one completely ungrateful, the other willing to endure anything for the kindness others showed him.
During his last visit to Kuwajima Jigorō's house, Musashi learned about Zenitsu's past: he had been swindled out of all his money by a woman and was heavily in debt when Kuwajima Jigorō found him. Kuwajima Jigorō paid off his debts and took him in as a disciple.
Unlike most other members who joined the Demon Slayer Corps, he didn't have many reasons to hunt demons; there was no direct hatred between him and demons.
Yet he still joined the Demon Slayer Corps, and despite his immense fear, he persevered until now because he wanted to live up to Kuwajima Jigorō's expectations…
"Kaigaku… he's dead… I killed him myself…"
Musashi said with a heavy voice. His heaviness wasn't because of killing Kaigaku, but because he had to tell Zenitsu about it.
"Ha… haha, you're joking with me, right?"
Zenitsu's pupils constricted upon hearing this, then he said in disbelief.
"I'm not joking."
Musashi replied to Zenitsu. He felt that Zenitsu should be able to bear it and had no intention of hiding it from him.
Zenitsu fell silent upon hearing this; he could tell that Musashi wasn't joking.
"Did Senior Disciple Kaigaku… do something?"
Zenitsu believed that Musashi wouldn't do this without reason. He understood Kaigaku quite well, and when something like this happened, his first thought was that Kaigaku had done something unforgivable.
Although Zenitsu respected his senior disciple, he couldn't bring himself to like him. Even though he had tried his best to get along with Kaigaku for Kuwajima Jigorō's happiness, he was still beaten, scolded, and ostracized by him.
"When I last encountered him, he was the new Upper Rank Six… he had already killed an entire village of people, and before that, there might have been even more innocent victims.
And he was fully conscious…"
Musashi replied to Zenitsu.
Upon hearing Musashi's reply, Zenitsu's body trembled slightly.
Zenitsu believed Musashi wouldn't lie to him about such a serious matter, but it was indeed difficult for him to accept at the moment.
"Does Grandpa know?"
After a moment of silence, Zenitsu asked Musashi.
Musashi sensed the worry in his voice and also noticed that Zenitsu's usual frivolity had vanished, and his expression was much more serious and solemn than before.
"Currently, besides us two, only Master Kagaya and Lady Amane know this news, and Master Kagaya has already agreed to keep it a secret.
If this matter were known by others or by Mr. Kuwajima, the punishment for Mr. Kuwajima according to the Corps rules would be very severe…"
Musashi replied to Zenitsu.
Zenitsu's hanging heart dropped slightly upon hearing this, and he also understood what Musashi meant by the punishment being very severe.
Nezuko, as Tanjirou's sister, became a demon. Even though she didn't eat humans, during her judgment, more than half of the Hashiras believed Tanjirou should be executed along with her.
And Kaigaku, as a disciple trained by Kuwajima Jigorō, abandoned his demon slayer identity to become a demon, even harming countless people and becoming the Upper Rank Six. If this matter were exposed, Kuwajima Jigorō's punishment would almost certainly be death.
"Thank you, Musashi…"
Zenitsu suddenly bowed to Musashi and thanked him aloud.
From Musashi's words, Zenitsu already understood why he did what he did. At this moment, he could only be grateful that it was Musashi who discovered and killed the demonized Kaigaku. He couldn't imagine what would happen to his grandfather if this coincidence hadn't occurred.
"About this… I think it's better if you don't tell Mr. Kuwajima."
Zenitsu nodded upon hearing this.
"I understand. I'll tell Grandpa that Kaigaku left the Demon Slayer Corps and went somewhere unknown. Although that will also make Grandpa sad, it's better than telling him the truth…"
Zenitsu's expression was somewhat dejected. He felt it was unfair to Kuwajima Jigorō in his heart, that a disciple he had painstakingly taught would one day completely disregard his life or death, and could even be said to want to put him to death.
Having lived in the Demon Slayer Corps for so long, Kaigaku couldn't possibly be unaware of what would happen to his trainer if he became a demon, yet he still did it.
After hearing Zenitsu's reply, Musashi felt a little relieved. Zenitsu's calmness made him feel that the other party had matured, although the process was somewhat painful for him.
"Musashi, can you guide me in my training these two days?" Zenitsu suddenly asked Musashi, his eyes filled with determination.
Musashi was somewhat surprised by Zenitsu's request. Before, when he guided Zenitsu in training, the latter had suffered a lot and was very resistant to it, yet now he was actively asking to be guided in his training.
Musashi understood Zenitsu's personality, so he could better comprehend the determination Zenitsu had made in making such a decision.
"Alright, I will do my best to guide you before the final battle begins. We can't waste your hard-won determination."
Musashi nodded and agreed.
"With something like this happening, Grandpa is the one who suffers the most…
He already had no choice but to choose us two to inherit Thunder Breathing because we couldn't learn the complete Thunder Breathing, and now Kaigaku has done something like this…
I can't run away anymore. Although I can't change what has already happened, at least I must try to make Grandpa feel some comfort…"
Zenitsu murmured to himself, the motivation he had lacked before now fully replenished.
...
That night, after Tamayo and Yushiro handed over a large number of talismans created by Yushiro to Kagaya, they also set off on their journey.
Muzan's blood, extracted from a demon's body, flew in one direction across the night sky. The two used Yushiro's talismans to become invisible and followed the blood, chasing it forward…