Follow the early escapades of Lina Inverse and Naga the Serpent as they cross paths for the first time. Their initial encounter involves a run-in with a vampire during a daring rescue mission. Subsequently, Lina takes on the role of a high-paying bodyguard for a wealthy man's daughter, Sirene, only to face the challenge of Sirene's extravagant spending habits. To teach Sirene a lesson, Lina orchestrates a fake kidnapping that backfires when Sirene is actually abducted, prompting a reluctant alliance with Naga to orchestrate a rescue. The tale culminates in a showdown where Lina and Naga find themselves on opposing sides in a dramatic fashion clash.