Tenkuu Shinpan Arrive

senya is just an ordinary guy, who wanted to become an astronaut as a kid. one day and suddenly, he's transported into another world after seeing on the rooftop of his school something like a “tower” going across the sky. there, he witnesses a ruined world, where skyscrapers are connected by suspension bridges. senya, perplexed, manages to see a girl standing on the roof of another building, as well as a masked man holding a bloody weapon in his hands…