Story:

“Ai was the first to notice the problem,” Violet said.

Across the library table, Peach tilted her head. “What problem?”

“Sending Shiro back to school.”

“Seira-sama?” Ai had stopped halfway to the chamber door.

Shiki turned. Behind her, the others paused. The twin’s voice trembled.

“But Aunty Shiro has grown ten years older. When she comes back… how can she still be a student?” Mai’s eyes widened.

Kicho looked at Violet.

For all their concern about finding Shiro, none of them had considered what her return would look like to the people who had known her before.

Seira stared at them. Then she sighed.

“Oh, wonderful. Must I explain quantum physics to a room full of monkeys now?”

“That,” Peach interrupted, “is exactly what frightened me.”

Violet stopped recounting the scene.

“When I woke up, everyone looked the same,” Peach said. “Reika. Miffy. Shiori. Nobody had aged. Then I looked in the mirror…”

Her fingers touched her cheek. “I thought I would see the woman who had lived at Yamato Shrine for ten years. Instead, I saw my schoolgirl face.”

Violet nodded. “We asked for an explanation. Unfortunately, we received it in Seira’s usual style.”

She sat a little straighter, adopting the Grand Miko’s imperious lift of the chin.

“‘Listen carefully. I will say this once. Remember it in case Momoka asks you later.’”

Peach almost smiled. Almost.

“Upon returning,” Seira said, “Momoka will constitute a singularity containing two states.”

Four faces watched her.

“One is the girl native to this world. The other is the woman who has spent ten years in yours.”

Mai cautiously raised a hand. “So which one comes back?”

“Both.”

Mai lowered her hand.

Seira rubbed her temple. “They are not mutually exclusive. Her original existence here and her accumulated existence elsewhere can coexist. The difficulty is how this world accommodates her return.”

Violet’s attention sharpened. “And how does it?"

“By recognizing the state that belongs within its own continuity: the high school girl.”