Sung-Rae, a high school boy disappearance after picking up a call on the streets. He lands in another world in one of the cities "Sassy City". There, he met Jin-ah and Yoon-Ae who helped him understand their world. Read more to find out about the other characters Ah Reum, Chae Eun, Mi Do, Devi, Jong and Ha Na and how they joined the journey.