"Goblin Slayer: Brand New Day" is a spin-off manga series set in the same universe as the original "Goblin Slayer." It consists of episodic, self-contained stories that expand on the world and characters while maintaining the dark, gritty tone of the main series. The narrative focuses on various adventurers and their encounters with goblins, often highlighting the dangers and moral complexities of their profession. The Goblin Slayer himself appears as a recurring character, but the spotlight frequently shifts to other members of the adventurer's guild, providing a broader perspective on the world.

The series explores the lives of both seasoned and novice adventurers, delving into their motivations, fears, and struggles. One story might follow a group of rookies on their first goblin-hunting mission, showcasing their inexperience and the harsh realities they face. Another might center on a veteran adventurer grappling with the trauma of past battles. The Goblin Slayer often serves as a mentor or a catalyst for these characters, offering his expertise and pragmatic approach to dealing with goblins, though his methods remain as ruthless and efficient as ever.

Themes of camaraderie, survival, and the moral ambiguity of adventuring are prevalent throughout the series. The episodic structure allows for a diverse range of characters and scenarios, from lighthearted moments of bonding among guild members to intense, life-or-death battles against goblin hordes. The world-building is consistent with the main series, emphasizing the low-fantasy setting where even minor threats like goblins can be deadly if underestimated.

Key characters include the Goblin Slayer, whose singular focus on eradicating goblins drives much of the action, and his companions such as Priestess, High Elf Archer, Dwarf Shaman, and Lizard Priest, who occasionally appear to lend their skills or provide insight. New characters are introduced regularly, each contributing to the overarching narrative of the adventurer's guild and its members' struggles. The series maintains a balance between action, character development, and world-building, offering a deeper look into the lives of those who inhabit this perilous world.