Hajime Ryujoji stands as the elder brother of Shiro Ryujoji and the true heir to the Ryujoji clan leadership, despite the initial perception of him being the second son. He leads the clan's centuries-old vendetta targeting the successor of Yagyu Jubei, Jiyu Nanohana, with the primary objective of fulfilling the clan's oath of vengeance by eliminating her.

To accomplish this goal, Hajime orchestrates the resurrection of Taiko Daiyu, the ancestral leader defeated by the original Yagyu Jubei 300 years prior. He facilitates Taiko Daiyu's return by allowing the ancestral spirit to possess his body, merging their identities. This act transforms him into the primary vessel for the clan's accumulated hatred and desire for revenge against the Yagyu lineage.

While possessed by Taiko Daiyu, Hajime exhibits heightened aggression and strategic cunning. He directs the Ryujoji clan's efforts to challenge Jiyu, manipulating his brother Shiro and other clan members into confrontations. His actions escalate the conflict, culminating in a decisive battle where Taiko Daiyu, using Hajime's body, faces Jiyu and her father, Sai Nanohana.

Following defeat in this confrontation, the spirit of Taiko Daiyu is exorcised from Hajime's body. Freed from the ancestral grudge and possession, Hajime undergoes a significant transformation. He expresses gratitude toward Jiyu for releasing him and the Ryujoji clan from the cycle of hatred that had bound them for centuries. This liberation allows Hajime and the clan to abandon their vengeful mission and integrate into modern society.