Satsuki Gokajou, the school’s athletics coach, boasts a boisterous, aggressive personality that champions physical prowess over intellectual debate. Her tomboyish energy mirrors her appearance—short blue hair, sharp blue eyes, and a habit of lunging into action, fists or shouts first. She clashes relentlessly with Uzuki Shitenno, the arts teacher, their fiery rivalry fueled by opposing worldviews.

A Spartan disciplinarian, she drills students with merciless training, yet softens unexpectedly around Minazuki Rokumatsuri, Chitose’s adoptive sister, offering rare gentleness. Bears define her aesthetic and antics: she dons bear-print pajamas, growls playfully, and deploys a signature cleavage-based headlock dubbed "The Booby Trap" during physical comedy skirmishes.

Her competitive streak leads to absurd feats, like facing Hazuki Yazakura in an eating contest that leaves her stomach grotesquely swollen. Though abrasive, Tsundere flickers emerge—like pinning Chitose in a lap pillow while growling a lullaby, blending menace with awkward care.

In *Happy Lesson: The Final*, she unites with fellow teachers to defend the school’s historic building from demolition, showcasing loyalty to their shared cause. While occasional warmth seeps through her rough exterior, Satsuki stays unapologetically fierce, thriving on rivalry, brute force, and unfiltered spontaneity.