A flying object is captured on camera, accompanied by mysteriously cheerful music from a radio. Hoping to uncover the truth, high schooler Yamada involves his classmate Ishioka into the investigation, and they enthusiastically continue their research. Meanwhile, an alien named Kuna eats at a Chinese restaurant without money, dines and dashes, and is rescued by a boy named Manobu.
Before long, their intentions begin to converge into a single intertwined storyline.