Kana and her friends design a bottle rocket and launch it into space, even though it might not get there at all. However, just when the rocket is completed, a robot suddenly crashes into and destroys it, shortly followed by a pink-haired woman claiming to be a "Galactic Investigator".
Hidomi Hibajiri is a young girl who never takes off her headphones. Her whole life consists of going to school, helping out at her mother's cafe, and listening to music. With nothing else to break the crippling monotony, she keeps her headphones on at all times. That is, until she is run over by a mysterious guitar-wielding woman.
Naota is a normal Japanese 6th grade boy (although a little cynical), but when his older brother leaves for America to play baseball, his brother leaves his 17 year old girlfriend Mamimi behind. Mamimi is sending mixed signals and advances to Naota, and he doesn't know what to do about her. But to make matters worse, Naota's world is totally turned upside down when he is run over by a woman on a Vespa. During their first encounter, she hits him over the head with her guitar, which then causes a horn to grow out of his forehead. She calls herself "Haruko" and her presence changes Naota's life to even further insanity