Bungo Stray Dogs: The Fushiguro Family's Artifact Forger

(The protagonist's secret identities include both men and women, but her soul is female. No romance.) A weapon-refiner from the cultivation world melded herself into a weapon. When she was reborn, she lost most of her memories. She was reborn as Megumi Fushiguro's twin sister. Unexpectedly, around the age of three, she was somehow taken to Yokohama. In the end, she subdued the other powers in the city and became its true ruler, freeing Yokohama from government control. Eventually, she used her own strength to return to her original body and entrusted all of Yokohama to Verlaine. But after returning to her original body, she discovered that she and her mother had been unconscious for more than half a year. During that time, her father had gone missing, and her young brother had taken on the responsibility of caring for them both. If Fushiguro Yu hadn't woken up in time, their family would have truly been torn apart. So Fushiguro Yu began the search for a way to awaken her mother, A fantastical world of scientific mystery