Tenkuu Shinpan Arrive  

High-rise Invasion Arrive, 天空侵犯arrive, Sky-High Survival arrive, Sky High Survival - Next Level

Senya was an ordinary boy with dreams of becoming an astronaut. One day, while observing something like a "tower" in the sky from his school's rooftop, he was suddenly transported to another world. In this new realm, he found himself amidst ruins, where towering structures were linked by suspension bridges. Confused, Senya spotted a girl on another building's roof and a masked man wielding a bloody weapon.