Seina Katsura operates as a pivotal member of the Best Student Council’s Covert Squad, skillfully coordinating missions and serving as the foremost operative under Kuon Ginga’s command. Her responsibilities include intelligence gathering and strategic oversight, balanced by a cheerful, courteous exterior that shifts seamlessly into focused intensity during operations. She collaborates closely with fellow council members, especially Kuon, and upholds unwavering loyalty to both the council and its president, Kanade Jinguuji.

Her lineage traces back to the Jinguuji family, though she bears a modified surname after being excluded from inheriting their supernatural legacy. This ties her to Kanade as a relative, though their specific familial connection remains undefined. Later, she ascends to chair “V,” an organization governing the Jinguuji family’s affairs, leveraging her position to discreetly aid Kanade’s campaign to dismantle the family’s oppressive traditions and reclaim autonomy.

Seina’s younger sister, Minamo Katsura, maintains an unspecified affiliation with the council, their relationship left largely uncharted. Renowned for her optimism and resourcefulness, Seina blends lightheartedness with tactical precision, cementing her reputation as an indispensable Covert Squad asset. Despite her non-magical heritage, her adept leadership within “V” underscores her administrative prowess and steadfast commitment to safeguarding the council’s objectives.