Liang Mingxia, daughter of martial arts master Liang Jian-Feng (who trained Narumi Kato), is Narumi's tomboyish childhood friend and a formidable martial artist. Her name reflects distinct meanings: "Liang" for "beam/ridge," "Ming" for "bright/clear," and "Xia" for "afterglow/dawn/red cloud."

She aids Narumi in safeguarding Masaru Saiga and confronting the Midnight Circus, specifically its automata forces. Her combat style capitalizes on a critical automata programming flaw: prioritizing terrifying audiences during performances forces them to drastically reduce speed against unarmed opponents. This allows martial artists like Liang Mingxia to effectively engage them with bare-handed techniques designed to disrupt their internal mechanisms.

Within the manga continuity, she also applies her martial prowess as an actress in action films. Her tactical ingenuity surfaces against the automaton Jack Gambler, a manipulator of gambling outcomes. Rather than submit to his rigged rules, she shatters his system with a precisely timed qi-powered punch during a coin toss.

Her relationship with her father remains professional, grounded in their shared martial arts dedication, though specifics of their interactions are less documented. Throughout the conflict, she operates primarily in a supporting role, directly engaging automata threats alongside Narumi and allies. Her contributions form part of the broader effort to counter the Midnight Circus's objectives.