Revenge, Who Does It Belong To?! (復讐するは誰にあり！？編 Fukushū suru wa dare ni ari!? Hen) is the eighth Black Lagoon omake. It was originally released in the ninth manga volume on October 19, 2009.

Outfitting herself with various weaponry, Roberta claims to Fabiola Iglesias that Garcia Lovelace was chopped up by a trap and therefore must get revenge. Confused, Fabiola asks her what her outfit is supposed to be, and Roberta responds that it is proper attire for a night assault. When the head maid remarks that they can "score thirty in one night" with their gear, Fabiola asks for clarification since she cannot understand her words. Yelling, Roberta loudly and rhetorically asks Fabiola if she does not want to get revenge for Garcia, ordering the child to leave behind her pay and smacking her in the face. Agreeing in hesitation, Fabiola wonders who exactly do they exact revenge on. Roberta points out that Garcia is sleeping and threatens to injure Fabiola if she even thinks of jumping the boy. Suddenly, Roberta screams and cleaves Garcia in the head, shocking Fabiola. The former covers her mouth and states that she had to do it because suffering is inevitable if the "young master" remains. As blood splatters onto Fabiola, she exclaims that Roberta's actions are wrong since they cannot discern their enemy.

Biting her fingers, the paranoid Roberta replies that their enemy is someone with small breasts. Smiling, she elaborates that small-breasted people conspired to murder Garcia and how they insult large-breasted women. Listening to her, Fabiola awkwardly realizes that Roberta can only express things that would be censored by the publisher. Roberta glares at Fabiola, scaring the latter, who asks Roberta why she is staring at her chest. As soon as Roberta runs at Fabiola with a knife, Garcia grabs her wrist and tells her that he does not care about breast sizes and that revenge will solve nothing. The head maid hugs Garcia and praises him for summarizing in four pages what happened in four volumes, but the boy asks her not to hug him so tight since he will bleed from his head further. Getting up while panting heavily, Fabiola glares at them and claims that the story is not over yet. Pulling out a sword, Fabiola claims that the real enemy is someone with large breasts since they insult small-breasted women. Running away from her, Roberta yells that she is infected while Garcia awkwardly stands and bleeds profusely.