下校途中に無差別爆弾事件に巻き込まれ、異世界へ飛ばされた女子高生・典子。見知らぬ森の中で怯える典子を救ったのは、渡りの戦士・イザーク。この2人の出会いから、世界は大きく動き始める――。
A high school girl, Noriko, is caught up in a random bombing on her way home from school and is sent to another world. A frightened Noriko in an unfamiliar forest is saved by a migratory warrior, Yzak. The world begins to move forward in a big way from the encounter between these two people.