The story is set in two distinct worlds. Tokio lives with other children inside a world surrounded by a beautiful wall, but one day he receives a message that reads, "Do you want to go outside?" Meanwhile, a boy named Maru travels with an older woman, eking out a meager existence in a ruined world as they search for "paradise."

Note: Winner of Kono Manga ga Sugoi! 2019 Award in Male Readers category.