In a not-so-distant future, nations invest heavily in scientific research to address food shortages. This leads to the discovery of new elements beyond the 119th. Tokyo scientist Hikojuro Araki creates Araraginium, the 256th element, capable of generating life from nothingness. However, during the inaugural experiment, an unexpected accident scatters Araraginium across Tokyo.

Days later, a strange phenomenon occurs: individuals presumed dead reappear, retaining memories from before their demise. Dubbed Araragi Humans, they emerge from the period between the accident and 72 hours prior.

This story unfolds in Tokyo years later…

• Shinsei Shonogamigakuen High School: Futuristic and contemporary, this school boasts a striking design. Its rooftop, enclosed by invisible walls, offers a haven for students during breaks.
• The Island Where Dreams Come True: Emerging post-Araraginium experiment, this Pacific miracle attracts tourists with its enigmatic beauty. Dense mangrove-like forests paint a surreal backdrop.
• Cafe CHIENYAROU: A haven for Tokimune and friends, this café brims with retro games, manga, and even a bowling alley. Japanese afternoon tea adds to its charm.
• Araragi Human: Individuals who perished between the accident and 72 hours preceding the Araraginium experiment. Though they appear as ordinary humans, they vanish instantly if no one observes them. To prevent this, the government employs “Invisible Watcher,” discreet surveillance devices installed on most Araragi Humans. Monitored around the clock by the government’s Araragi Watcher organization, these devices ensure their continuous visibility, averting their disappearance.
• “Elements” in this story: When we refer to “elements” here, it’s not about atoms. “Element” serves as an abstract concept containing properties. For instance, Araraginium isn’t an atom with 256 protons. Elements past the 200th differ greatly from atoms, described by protons and neutrons. Many are comprised of minuscule elements smaller than protons and invisible elements. These are known as Gaia elements. The detailed explanation of Gaia elements is too complex for high school students, so we won’t delve into it. However, Hamakado seems to grasp the concept well. If you’re curious, we suggest asking her.