Tenkuu Shinpan

From Seven Seas:
On the roof of a high-rise building, a young girl named Yuri witnesses a masked figure split a man’s head open with an axe! It’s not exactly an everyday occurrence for a high schooler, but things only get weirder from there. Yuri soon finds herself in a strange world of skyscrapers with only two options for escape - fight past the mysterious masked figures or leap to her death.