Black Lagoon: Roberta's Blood Trail
English name: Black Lagoon: Roberta's Blood Trail
Genres: Action
Type: OVA, Episodes: 5
Aired: Jun 27, 2010 to Jun 22, 2011
Studio: Madhouse
Source: Manga
Rating: R+ - Mild Nudity
Synopsis:
Crime never sleeps in Roanapur, and neither does Roberta—a devoted maid and skilled guerilla soldier in service to the Venezuelan Lovelace family. After the assassination of her superior by the US Secret Service, Roberta returns to the city of debauchery in search of vengeance and his killer's head.

Meanwhile, young Fernando Garcia Lovelace, the new heir to his father's estate, tails Roberta to Thailand alongside his bodyguard, Fabiola Iglesias. He enlists the help of the Lagoon Company, with the objective of deterring Roberta's warpath and bringing her back to the family. However, with the continued bloodshed and mounting tensions between Roberta, island crime factions, and the US military, it will take a significant amount of strategy—and weaponry—to stop her relentless quest for revenge.