Airi is an average 12-year-old girl. She goes to school, hangs out with her friends, and loves being outdoors. The thing is, she can only be outside for 30 minutes a day. Welcome to Airi’s life. A catastrophic nuclear war reduced the world to a radioactive wasteland and forced her and other humans to live deep underground. But, this doesn’t bring Airi or her friends down. As they explore aboveground, they make shocking discoveries not taught in school.