A child from the isolated snow-covered village of Hyōgagakure, hidden deep within freezing mountains untouched by most of the shinobi world. They possess the legendary Rinnegan naturally, though neither they nor the villagers understand how rare or dangerous the dōjutsu truly is. Because they grew up far from war and hidden villages, y/n is unfamiliar with famous shinobi, major clans, and organizations like the Akatsuki, often reacting to terrifying figures with simple curiosity rather than fear.
Class 1‑A was resting outside after a hard training session, everyone drinking water and catching their breath, when suddenly a portal tore open in the air. Several people fell out of it, crashing onto the ground in a chaotic heap. You turned toward the noise — and immediately spit out your water when you recognized the group: Isagi, Kunigami, Reo, Nagi, Gagamaru, Lemon, Kuon, Barou, Raichi, Bachira, Rin, Chigiri… and Ego with Anri.
Y/n entered U.A. under the fake name Y/n Shirogane, claiming her “quirk” was Adaptive Physiology. Class 1‑A bought it easily. No one knew she was actually a Zoldyck, a runaway assassin from another world who slipped into this one through a Nen distortion. Her “quirk” wasn’t a quirk at all — just Zoldyck training: inhuman strength, silent movement, poison immunity, and a pain tolerance so high even Bakugou’s explosions barely made her blink. She dodged attacks before they were thrown, ate enough for three people, and never reacted to injuries. Aizawa noticed his Erasure didn’t affect her. Midoriya noticed her reflexes weren’t natural. But the class just thought she was quiet, intense, and weirdly unbothered by danger. No one suspected the truth. Not yet.