Ever since he was a child, Tomoki Sakurai has always woken up in tears after dreaming of an angel. His childhood friend, Sohara Mitsuki, worries about this and decides to seek the help of Eishirou Sugata, an eccentric sky enthusiast. Eishirou concludes that Tomoki's dream is undoubtedly connected to what is known as the New World, a floating anomaly that scientists have failed to understand. Recruiting the first members of the New World Discovery Club, Eishirou schedules a time for them to meet in order to observe the mystery in the sky. That day, Tomoki's peaceful life is changed forever when a strange girl falls from the sky and begins to call him master. Sora no Otoshimono follows the daily activities of the New World Discovery Club as they begin to learn more about the Angeloids that have arrived on Earth.