Futaba Isurugi is a second-year student in the Actor Training Department of Seisho Music Academy's 99th Graduating Class. She shares an eighteen-year bond with childhood friend Kaoruko Hanayagi, marked by Futaba habitually tending to Kaoruko's needs—transporting her via motorcycle and handling labor Kaoruko shunned. This created a "rotten" dynamic where Futaba's vocal complaints masked steadfast devotion.

Beneath her rough exterior lies kindness. Petite yet physically formidable, she excels in staged combat, wielding a shortened German halberd with lethal precision. Her athleticism shines in sword fights.

A turning point arises when Futaba confronts their codependent stagnation. During a revue, she declares a "straight path of parting," directly challenging Kaoruko's selfishness and her own enabling role. She stakes their dysfunctional relationship on this decisive match, vowing to forge independence.

This resolve leads Futaba to join the New National First Theater Troupe, separate from Kaoruko. Symbolizing their parting, she entrusts her cherished motorcycle—once Kaoruko's transport—to her friend. She commits to driving her own limitless road, refusing to let either's potential go unfulfilled.

Visually, Futaba sports amaranth pixie-cut hair and amethyst eyes. Her revue costume pairs a gold-piped purple jacket with standing collar, white turnbacks, and red cuff flaps over a white shirt, plus a pale-purple knife-pleated skirt and gold-trimmed black boots. Her halberd's gem uniquely blends her and Kaoruko's colors, mirroring her stage goddess attire.

Background: Trained in Senka-ryu Traditional Japanese Dance since 2005 and gymnastics at Shimogamo Action Club since 2010. Participated in the 2014 Traditional Dance Federation's "Cherry Blossom Viewing Festival" and placed third in the National School Council's New Year Dance Performance (2015, 2016). Prefers kinako sticks, meat, cheap candy, and snacks; dislikes fish and inactivity.