Eighty-one Holy Grail Bombs.
The mention of this made Okita freeze for a moment.
"What… is that, Master?"
"Literally speaking… well, let me explain from the beginning."
As he spoke, Naoki rose to his feet—and suddenly, a whiteboard appeared behind him, identical to those used by tutoring instructors.
In truth, he had simply manifested it based on that image.
With a black marker, he drew a Holy Grail on the board. He tapped it lightly. "Alright, Okita, Angelica—look here. As I explained earlier, in this Singularities, the Holy Grail War already occurred once, two years ago. But when the War reached its peak, all Servants and the Grail vanished… only to reappear two years later."
"But the Grail didn't vanish—it was stolen. Archer—Oda Nobunaga—took control of the Imperial Japanese Army and used its military power to steal the Greater Grail, hide it away for two years, and prepare to realize her ultimate goal."
Naoki continued, sketching a small figure of Nobunaga and drawing an arrow pointing toward it. "So the question is—what does Nobunaga and the Imperial Army intend to do with the Holy Grail? When we combine this with the context of this era, the answer becomes obvious."
It is currently 1945—the year known to everyone in the future as the end of World War II, where the world achieved victory in the anti-fascist war. But that applies only to the Allied powers. As one of the Axis nations that started the war, Japan was the defeated side.
It's easy to imagine: soldiers whose minds were saturated with honor and the Yamato spirit could never accept defeat. For this war, Japan had poured everything into it—and they would never allow it to end in loss.
Therefore, naturally, the Japanese military conceived the idea of using the Holy Grail. With a device capable of granting any wish, surely they could reverse the course of the war.
"These idiots who don't understand Magecraft probably only think like this." Naoki scoffed. "But Nobunaga is different. After two years of studying the Grail—with possible assistance from a certain Magus—she realized the Holy Grail isn't truly an All-Wishing Machine."
"So she abandoned the idea of saving her nation by petitioning the Grail, and instead chose to modify the Greater Grail itself—transforming it into something far more devastating."
Adding the word "BOMB" next to the Grail drawing, Naoki continued.
"The Eighty-First Holy Grail Bomb—a magical weapon that shatters the Greater Grail into eighty-one fragments and reassembles them into something entirely new. A strategic weapon capable of altering the outcome of war with a single detonation."
"Considering the sheer amount of Mana contained within the Greater Grail, its explosive power could potentially obliterate the entire Imperial Capital."
A strategic weapon capable of annihilating the entire Imperial Capital?
Okita's expression instantly turned grave. "That would cause catastrophic casualties… and likely alter the very structure of the world, wouldn't it?"
Naoki nodded. "Exactly. If that thing detonates, I don't know whether it will 'save' the nation—but Japan itself will be erased. I have no idea what the world will become afterward. The Second World War, expected to end this year, might drag on indefinitely. This deviates entirely from human history."
"Therefore, to correct the Incineration of Humanity, our task is simple: destroy the Eighty-First Holy Grail Bomb. The Grail is the root of this Singularities. If we destroy or reclaim it, this Singularities will collapse naturally. From this perspective… yes, we are indeed the great sinners Nobunaga said would destroy the world."
Okita smiled at this. "If thinking like this makes us great sinners, then I'll gladly become one—even if I have to do it a hundred times over, alongside my Master. Nona Angelica agrees too, right?"
"Without question." Angelica's gaze was steady and unwavering. "I am Natsukawa-sama's possession. Natsukawa-sama's will is my will. I will act only as Natsukawa-sama commands."
The unwavering loyalty displayed by both of them in succession left Naoki momentarily speechless. "You two… Well, Angelica has been like this for over a decade; I've given up trying to change her. Sometimes I wish you'd learn from Rei and Manaka. They're dolls too—but they don't see me as their master."
"As for Okita… don't worry. Whether you like it or not, I'm keeping you by my side until the very end."
"—!"
At Naoki's words, Okita's body trembled slightly before she bowed her head deeply, voice choked with emotion. "Thank you so much, Master! Okita Souji will never betray your trust! Even if my body and blade are shattered to pieces, I will fight until my final breath!"
"No, I didn't ask you to go that far…"
Seeing Okita's reaction—exactly as he anticipated—Naoki felt equally overwhelmed.
Servants respond to the Holy Grail's call because they harbor a desire they wish fulfilled. Artoria wished to save Britain; Iskandar sought a physical body… Okita was no different. Yet her desire wasn't one that required the Grail to manifest.
Similar to Diarmuid's vow to "remain loyal to his lord until death". Okita's deepest wish was to "fight until the very end."
During her life, plagued by a terminal illness, Okita had been unable to die fighting beside her Shinsengumi comrades. Though she understood their desire for her to live, she still longed to face her end on the battlefield alongside them—not in a hospital bed.
This was the only wish she ever carried in her heart.
Hence, her reaction now. Naoki's words confirmed her soul's deepest longing. For a samurai, there could be no greater fortune than having a master who understood her heart so completely.
(Though admittedly… my way of understanding her heart is a bit cheap…)
"Then, let me outline our operation. Based on my senses, the Holy Grail Bomb hasn't been completed yet. Its exact stage of development remains uncertain—perhaps the fragments are still separated and unreassembled, or perhaps they've already been assembled and are awaiting final activation."
"So our next step is clear: locate the Holy Grail Bomb somewhere in the Imperial Capital and destroy it. Afterwards, I'll mark every Imperial Army base across the city on the map. Starting tomorrow, we'll infiltrate and investigate each one individually—we don't know precisely where it is, so we must eliminate possibilities one by one."
"As for tonight…"
Naoki dismissed the whiteboard behind him with a wave, smiling gently. "It's late. Let's get some sleep."