Hello!
High-Rise Invasion is a Japanese manga series written by Tsuina Miura and illustrated by Takahiro Oba.
Ref: https://www.kobo.com/pt/pt/ebook/high-rise-invasion-vol-19
High school girl Yuri Honjō is transported to a world full of skyscrapers and suspension bridges connecting them. She then finds herself being hunted by mysterious figures wearing masks. She later discovers that her brother, Rika, is also trapped in this world. She thereupon encounters other teenagers in the same situation, but it is not clear if they will be friends or foes.
@criptomaster