Having been demoted for failing to prevent the murder of one of his superiors, Mondo is startled by a group of masked thugs who are soon attacked in turn by an unseen force. He begins to suspect the work of assassins, but whose side are they on?

Akio, who works at a gas station, earned his large motorcycle license and finally got his hands on the GSX1100S KATANA he’d always wanted. Devoting more affection to his bike than to his girlfriend Risa, he silently continues to test-run the engine. One day, Akio meets Mioko, a tough-talking junior at Risa’s high school. She had a crush on Akio’s friend Takashi, but at the same time, she had caught the eye of Kikuchida, a member of a delinquent gang.