"Worst Gaiden: Guriko" is a spin-off of the "Worst" manga series, which itself is part of the larger "Crows" universe created by Hiroshi Takahashi. The story centers on Guriko, a former delinquent and member of the Housen Academy's infamous Armament Riders, a group known for their violent and chaotic behavior. Guriko, whose real name is Tatsuya Guriko, is a complex character with a troubled past, marked by his involvement in gang violence and his struggle to find purpose beyond his reputation as a fearsome fighter.

The narrative delves into Guriko's life after his time at Housen, exploring his attempts to leave his delinquent past behind and reintegrate into society. Despite his efforts, Guriko finds it difficult to escape the shadow of his former life, as his reputation continues to haunt him. The story examines themes of redemption, identity, and the lasting impact of one's actions, as Guriko navigates relationships with old acquaintances and new challenges.

Key characters include Guriko's former comrades from Housen, such as Bouya Harumichi, who plays a significant role in Guriko's journey. Their interactions highlight the bonds formed through shared experiences of violence and survival, as well as the difficulty of breaking free from the cycle of delinquency. The manga also introduces new characters who challenge Guriko's worldview and force him to confront his past decisions.

The plot is driven by Guriko's internal conflict and external pressures, as he faces threats from both old enemies and new adversaries. The story balances intense action sequences with moments of introspection, providing a nuanced portrayal of a man striving to change his life while grappling with the consequences of his past. "Worst Gaiden: Guriko" serves as a character study, offering a deeper understanding of Guriko's motivations and struggles within the broader context of the "Crows" universe.