The High School Episode (高校編 Kōkō-hen) is the first Black Lagoon omake. It was originally released in the first manga volume on December 12, 2002, and it was later animated and released on the first Japanese Blu-ray disk on December 23, 2009.

Wondering why he is wearing a high school uniform, Rock then wonders what roles other people will play in the omake. Walking heartily, Revy sings a song and greets Rock, who looks at her awkwardly until Roberta greets him. Seeing Roberta smiling and in a school uniform, Rock smiles and thinks to himself that "there is a God" since she appears to be normal. Immediately, Roberta begins swinging a combat knife, disappointing Rock. Class then commences, with the teacher Balalaika calling for attendance and smoking a cigar. Looking at Rock, she asks him what he is staring at and glaringly asks him if he wants to die. He nervously denies any wrongdoing, and he wonders where Dutch is. Barging into the classroom, Dutch appears in a groundskeeper uniform and demands to know which student wrecked his flowerbed outside, surprising Rock. Elsewhere, Benny skips school and stays home to troll internet forums on his PC, and mutters insults at the screen in his dark bedroom.