On November 22, 2010, Japan endured missile attacks that were fortunately harmless to people, a terrorist incident later dubbed "Careless Monday." The event slipped from public memory and life carried on as usual. Three months later, during a graduation trip to the United States, college student Saki Morimi"s world shifted when she was rescued from an unforeseen crisis by Akira Takizawa. Takizawa is upbeat, yet strange in many respects—he appears naked, suffers from amnesia, and thinks he is a terrorist. He also wields an odd cellphone that holds 8.2 billion yen in digital funds. Despite his suspicious quirks, Saki quickly becomes friends with the mysterious young man. Unbeknownst to her, this marks the start of a suspenseful death‑match that revolves around money, phones, and global salvation. Higashi no Eden follows Saki"s quest to uncover the truth about her savior, while Takizawa confronts other rivals who possess similar phones and memories that hint at his possible link to the incident months earlier.