Map of the Sounds of Tokyo is the story of Ryu (Rinko Kikuuchi), a lonely young woman working at a Tokyo fish market at night. This official boring job is in fact not her only occupation, as she leads a secret life as a professional hitlady for high-paying clients. One day, Ishida (Hideo Skaki) approaches her for a job. He is the assistant of Mr Nagara (Takeo Nakahara), a powerful and wealthy businessmen. Mr Nagara is devastated by the loss of her daughter Midori, who took her own life after a violent breakup with her boyfriend David (Sergi Lopez). David is a handsome Spanish wine dealer and Mr Nagara considers him responsible for Midori's death. Ishida was secretly in love with Midori and wants David dead as revenge. This is the mission of Ryu, but when she meets David for the first time, she can't resist to his good looks and charm.