Shihoko Sakaki, a blue-haired freshman at St. Ignacio’s School for Girls, maintains a timid, fragile exterior that belies her resolute spirit. Childhood friends with Saori Tachibana, she joins the Etiquette Club alongside Saori and Kanami Ezaki after Rie Shibusawa’s impassioned speech stirs her to action. Secretly a front for the Exters—an organization deploying advanced mechanized Battle Skippers—the club is overseen by Reika Ayanokoji. Shihoko pilots the green Battle Skipper *Grand Buster*, equipped with hybrid weaponry tailored for tactical versatility.

Earnest and fiercely dedicated, she idolizes Rie as an older sister, channeling her admiration into growing self-assurance. Her evolution from hesitant recruit to pivotal team member unfolds through relentless dedication to missions against adversarial threats, her quiet resilience cementing her role in the group’s strategic successes.