In Tomboy Supremacy, a former US Army veteran reunites with his family in Southern Missouri after an absence of four years, confronting a multitude of obstacles upon his return. He must navigate the tsundere tendencies and brotherly attachment of his younger sister Cheyenne, while also grappling with his other younger sister Mary-Sue, who finds herself locked in a bizarre conflict with the squirrels of Greene County, MO. Additionally, he must contend with his older half-sister Luna, who shares her consciousness with the unpredictable persona of an alcoholic teddy bear named Cozmo.