Aozaki Aoko Case File

It's been almost a year since Aoko Aozaki and her little sister, Touko, caused a ruckus at the Clock Tower.

 Since then, Misaki Town has been eerily peaceful. Even Ritsuka Suzuse, a spy for the Mage's Association, quietly left the area without explanation.

Ritsuka once served as Aoko's tutor when she was a child, though their lessons often ended in disaster. Aoko, being no ordinary child, frequently stumped her tutor with tricky questions, leaving Ritsuka speechless and eventually fleeing in frustration. However, the real reason for Ritsuka's departure wasn't her lack of knowledge—it was because Aoko exposed her as a woman disguised as a man.

Sharp-eyed Aoko noticed something off about her tutor's physique and tattled to her father, leading to a trust crisis between the family and their deceptive tutor. After all, who cross-dresses just to tutor kids? In any case, Aoko didn't need a tutor; it was just her father's way of trying to give her a head start over other children.

Before Aoko's outburst at the Clock Tower, Ritsuka still loitered around Misaki Town, mainly to keep an eye on her sister, a nun at the local Aida Church. But when Aoko's ruthless side and combat prowess became widely known in the magus community, many dubious individuals, including Ritsuka, vanished from Misaki Town altogether.

Aoko didn't bother inquiring with Ritsuka's sister, Yuika, about her whereabouts. To Aoko, Ritsuka was a minor character not worth her attention, and their mutual indifference suited both parties.

Ironically, this made Misaki Town—with its distorted leylines—a calm eye in the storm of supernatural chaos. While Dead Apostles, vampires, and rogue magus stirred trouble elsewhere, Misaki Town became a tranquil sanctuary in the magical world.

...

"Five more centimeters taller!"

Touko beamed as she admired herself in her bedroom mirror, proud of her recent growth spurt.

"At this rate, I'll be back to my original height soon!"

The Grand Puppeteer's optimism wasn't just about height. Her second growth spurt had increased her number of magic circuits to an impressive 22—two more than before! For Touko, this was easily the best news she'd had after years of setbacks.

As she daydreamed about her bright future, her door suddenly slammed open.

"Can't you knock first?!"

Touko snapped, glaring at her sister, Aoko. Internally, she fumed at her sibling's lack of manners.

"Don't sweat the small stuff, Touko," Aoko said casually, sauntering in. She plopped into a chair and tossed a letter onto her sister's desk.

"What do you mean, 'small stuff'? And whose letter is this?"

Touko asked indignantly as she snatched it.

"It's from the Einzberns," Aoko replied.

"You remember the Holy Grail ritual I mentioned? It's about to start. Take a look."

Touko quickly opened the letter and began reading. The matter was too significant to ignore—it involved the Heaven's Feel ritual and her potential acquisition of the Third Magic. For any mageus, the allure was irresistible.

"Hmm… they've confirmed a curse?"

Touko murmured, scanning the contents.

"Before activating the Heaven's Feel, they need to purify the Greater Grail…"

"Well? Any ideas?"

Aoko asked, her eyes gleaming with anticipation.

"Even my magic can't separate Avenger's soul from the Greater Grail—that's the domain of the Third Magic."

"No problem!"

Touko declared confidently.

"I might not have focused on soul transfer technology before, but it's not beyond me. Besides, the Einzbern data has already helped me analyze the Greater and Lesser Grails. As long as we beat the other participants, the Grail's fruit is ours for the taking!"

"Soul transfer is conceptually similar to the soul duplication work I've done," she continued.

"They're like different facets of the same prism—similar construction, different effects."

"How long will it take?"

Aoko pressed.

"According to Acht's intel, the Grail War is about to start."

"I'm ready anytime," Touko assured her.

"But first, I need to locate the Greater Grail in Fuyuki. How should we proceed?"

"The Greater Grail is buried in the cavern beneath Ryuudou Temple on Mount Enzou," Aoko explained.

"It's a critical leyline nexus. I plan to rendezvous with the Einzberns and establish our base at the temple—it'll make future operations easier."

"Won't others know about such a prime location?"

Touko questioned.

"Leyline nodes are always contested."

"Fuyuki's significance has been deliberately obscured," Aoko replied. "Very few in the Mage's Association are aware of the Grail War's specifics. They'll likely send just one or two representatives. Our participation, coordinated with the Einzberns, is confidential."

"What about that magus killer?"

Touko asked.

"I wouldn't trust him as an ally."

"Kiritsugu Emiya is untrustworthy," Aoko agreed.

"But he's a small fry, easily dealt with. It's also why I don't want to use the Einzbern castle in Fuyuki as our base."

"We'll pose as two separate teams during the ritual," Aoko continued. "This way, we can opportunistically eliminate other participants when needed."

"Isn't that cheating?"

Touko teased, though her tone betrayed little disapproval.

"Cheating is a proud tradition of the Grail War. Don't like it? Don't play."