In a near future where food shortages drive intense scientific research, Tokyo scientist Hikojuro Araki synthesizes Araraginium — the 256th element — capable of generating life from nothing. A launch experiment goes wrong and Araraginium scatters across Tokyo. Days later, people who were presumed dead begin reappearing with full memories intact from up to 72 hours before the accident. These returning figures are called Araragi Humans. Years later, their existence is still reshaping Tokyo.