Yumi and Emi Hanner, twin daughters of retired Admiral Robert Hanner—a decorated war hero—first emerge during a hostage crisis orchestrated by Raalgon agents masquerading as anti-war extremists. The incident, which traps their father, family friend Yuriko Star, and the sisters themselves, is abruptly disrupted by Justy Ueki Tylor. His accidental intervention during a routine pension delivery dismantles the terrorists’ bomb plot, spurring the twins to enlist in the United Planets Space Force. Capitalizing on their father’s prestige, they secure posts aboard the Soyokaze under Tylor’s command.

Inseparable in both speech and action, the sisters mirror each other’s fierce determination, often voicing thoughts in unison or seamlessly continuing each other’s sentences. Their steadfast loyalty anchors them firmly as Tylor’s most reliable allies, defending his unconventional choices even amid crew skepticism. This allegiance deepens into romantic pursuit, with both openly vying for his affection.

Initially adrift without clear responsibilities aboard the ship, their frustration mounts until they confront ace pilot Kojiro, demanding flight training. Though resistant due to ingrained biases, Kojiro reluctantly acknowledges their raw talent, evolving into a grudging mentor. Rigorous practice hones their instincts, culminating in operational deployment as combat pilots renowned for precision and daring.

Their synchronized presence—marked by a split hairstyle forming a cohesive whole when side by side—weaves into the Soyokaze’s crew dynamics, tempering Tylor’s eccentricities and Kojiro’s brashness. Through their evolution from civilians to combat-ready pilots, their core identity remains unshaken: an unyielding optimism and dual devotion to Tylor, unchanged by the demands of service.