The 2020 Tokyo Olympic Games were halted abruptly in 2025 by a terrorist group. The site is now under the control of the United Nations and is beyond Japanese jurisdiction. Hana Togetsu, a seventeen-year-old student in an exclusive UN unit, is assigned a mission to Enoshima Island. She must attend a public school and meet a boy named Shunichi Nanase. However, just before Hana can make contact with Shunichi, an older man seeks him out. The situation grows more dangerous when the American military arrives, pursuing the man. A second teenage girl arrives on Enoshima Island to aid in the crisis.