Kuroko Usami’s long black hair flows into a ponytail, her uneven bangs obscuring a lace-covered left eye, while a faint scar marks her right eye without hindering her sight. Her extravagant lace gloves, dress, and heels accentuate a theatrical elegance.

As the Uesugi Band’s chief tactician, she masterminds the Awaji Island Recapture Operation, deploying decoys to lure oni and exposing spies within their ranks. After capturing Michiru and Musashi during a black crystal’s emergence, she imprisons Musashi but leaves Michiru unrestrained—leveraging the latter’s movements to intercept enemy signals and uncover bases.

In combat, she channels blade energy to cauterize Michiru’s injuries, halting blood loss. Allying with Kanetatsu Naoe, she battles oni and the Obsidian Eight, discerning Musashi and Michiru’s ties to the obsidian goddess. Her shrewdness exposes spies by exploiting their instinctive disregard for trampling clan crests.

During the conflict’s climax, she engineers fiery distractions to mask allies’ approach toward Yamata no Orochi, while covertly coordinating with Naotora Takeda to simulate discord and misdirect foes. Her strategies outmaneuver enemy countermeasures: rerouting bomb shipments, breaching Kitetsu blade seals with elite units, and cementing the Uesugi Bushi’s triumph.

The surname Usami—rooted in terms for "eaves," "aid," and "beauty"—honors a historical retainer of Uesugi Kenshin. Her name weaves motifs of beauty marks, unseen stagehands, and dark moles, reflecting the dualities shaping her design and role.