Black Lagoon: Roberta's Blood Trail (2010)

When the head of the Lovelace family is assassinated by soldiers from the U.S military, the maid of the family, Roberta - declares war on the U.S government and goes on a hunt for revenge. The heir and son of the murdered head of the Lovelace family, Garcia, goes after Roberta in a desperate effort to try and stop her. He hires the Lagoon Company for help.