Heaven's Lost Property Tomoki Sakurai is a young man whose motto is "Peace and quiet is the best", but he finds it difficult when he has to put up with his next door neighbor with a killer karate chop, Sohara Mitsuki; Eishiro Sugata, an eccentric scientist bent on discovering the "New World"; and Mikako Satsukitane, a borderline sadist. One day, while he was witnessing a strange anomaly in the sky, a UMA (Unidentified Mysterious Animal) falls from it. What falls from the sky is an Angeloid named Ikaros, who soon becomes Tomoki's servant. From then on, more Angeloids come to him, and with this, he finds himself struggling for his peace and quiet, but at the same time finds pleasant things the Angeloids bring him.