Hyou Shusui hailed from the Hyou clan, renowned for their supernatural abilities and lineage of priestesses. Began her journey as a priestess at the Hyou shrine before ascending to chief lady-in-waiting in the imperial harem and joining the "Wolves of the Wind," an elite assassination unit under Kou Shouka’s command. Her early years included a fleeting encounter with Ran Shuuei, who was instantly smitten, though the memory faded from her mind.

During a critical mission to the Hyou shrine in Kyuusaikou, Hyou Ruka—a formidable priestess scheming to control the imperial succession—trapped her in temporal stasis. Ran Shuuei’s daring rescue forged mutual respect, paving the way for their eventual marriage and the birth of three sons, including Ran Shijaku.

A pivotal shift occurred when Hyou Ruka’s spirit seized control of Shusui’s body, forcing her to target Emperor Ryuuki under Ruka’s command. Shuuei shattered the enchantment by invoking Shouka’s name, briefly reclaiming her will. This clash exposed her susceptibility to Hyou clan mysticism and the enduring shadow of Ruka’s ambitions.

Her past intertwined with unspoken affections for Kou Shouka, whose union with her mother, Hyou Shokun, entangled familial loyalties. Shusui’s bond with Shouka shaped her emotional journey, intertwining with Hyou clan politics and supernatural strife.

In subsequent years, she mediated political tensions between the Hyou clan and the imperial court, leveraging her dual heritage as both a former priestess and Ran clan matriarch. Her decisive actions during the Kyuusaikou crisis—confronting possessed allies and navigating treacherous loyalties—highlighted her resilience against supernatural and political dangers.

Her story culminated in a steadfast dedication to her family and the Hyou clan’s legacy, harmonizing her sacred past with her pivotal role in reconciling ancient rivalries.