In the confines of protected walls, youngsters are nurtured by robots in a nurturing environment reminiscent of a nursery. Though life seems monotonous within, the children brim with untapped potential and curiosity, akin to a slice of paradise. Beyond the walls lies a desolate wasteland devoid of technology, now home to enigmatic and formidable supernatural entities. Maru, accompanied by Kiruko, ventures into the remnants of Tokyo in search of their version of paradise. However, as their quest unfolds, they begin to question whether heaven is a tangible goal or merely an elusive fantasy.