Three people sit separately on a bus ride through Tokyo, Japan. Tetsu calls himself a “professional toilet cleaner,” which is an accurate description of his day job. Kasuya is a low level police officer, who dreams about working in the homicide division. Saki is a young girl, who wears dark sunglasses to hide a disfigured right eye. Their lives are about to become intertwined when a fourth person on the bus, pulls out a gun and hijacks the bus. He orders the bus driver to keep driving around the city, while he torments the other passengers with his suicidal tendencies. Tetsu does not want any part of this and tries to get the bus driver to stop. He is shot immediately, and then the person turns the gun on himself and commits suicide. A few months later Kasuya sees Tetsu walking in a subway terminal. He watches as Tetsu starts a fight with a whole group of well dressed loiters in the subway. Kasuya bails him out by flashing his badge and claiming to be arrestting Tetsu. Once they leave, they hang out together and talk about their depressing lives. Tetsu comes up with an idea to channel their angst in a constructive manner. They go to various public restrooms and offer their services, to anyone wanting to seek revenge. The first two jobs is executed spectacularly, but things start to go seriously awry by the third job. Saki is their fourth customer, and she wants nothing more than to blow up the entire city of Tokyo.