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...

A young man has a chilling dream. He is in a cold, dark hallway, gripping a knife in his hand. But when the terrors he encounters bleed into reality, nobody is safe...

The story follows a high-school student named Kei Nagai who is caught in a traffic accident, dies, but immediately revives and learns he is not human, but an Ajin, a mysterious creature that cannot die. Scared, he runs away from humans hunting him down but is helped by his friend, Kai, who joins him in his flight from civilization. He then becomes involved in a conflict between human and Ajin and must choose a side.

Note: Only the first volume is credited to MIURA Tsuina; all subsequent volumes were written and illustrated by Sakurai Gamon.

Nominated for: (1) 7th annual Manga Taishou Award, (2) Readers Award in the 18th Tezuka Osamu Cultural Prize, (3) 38th Annual Kodansha Manga Awards (2014) in the Seinen category, (4) 40th Kodansha Manga Awards (2016) in the General category.

High-school girl Yuri suddenly finds herself on the rooftop of a high-rise building. She's trapped in a bizarre world surrounded by skyscrapers, where a masked man cracked open a man's head with an axe before her eyes. Finding a way to survive this bizarre world, find her beloved brother, and escape becomes her top priority, but she is beset by danger not just from the mysterious Masks, which possess both inhuman strength and cruelty, but other survivors turned cruel or desparate by the insanity of the high-rise world.