The 257th Element

The 257th Element is a story set in Tokyo years after an accident scatters Araraginium, a newly discovered element that can generate life from nothingness. Scientist Hikojuro Araki created it while researching ways to address food shortages. During its first experiment, the accident also leads to people presumed dead reappearing with their memories intact.

Araragi Humans

Araragi Humans are people who died between the accident and 72 hours before the Araraginium experiment. They look like ordinary people but vanish instantly if nobody observes them. The government equips most with “Invisible Watcher” surveillance devices, while its Araragi Watcher organization monitors them around the clock to keep them visible.

Places in Tokyo

• Shinsei Shonogamigakuen High School: a school with a futuristic and contemporary design. Its rooftop is enclosed by invisible walls and serves as a place for students to spend breaks.
• The Island Where Dreams Come True: a Pacific island that appeared after the Araraginium experiment. Tourists visit for its mysterious beauty and dense, mangrove-like forests.
• Cafe CHIENYAROU: a gathering place for Tokimune and friends, with retro games, manga, a bowling alley and Japanese afternoon tea.

Elements and life

In the story, “elements” are abstract concepts that contain properties, not necessarily atoms. Araraginium, for example, is not an atom with 256 protons. Elements beyond the 200th differ greatly from atoms described by protons and neutrons; many consist of tiny elements smaller than protons or of invisible elements, collectively known as Gaia elements. Hamakado appears to understand Gaia elements well.