Lingyin Huang, known as Rin, is a Chinese transfer student representing China at the Infinite Stratos Academy. She pilots the Shenlong IS unit. Petite in stature, she has light brown hair typically worn in long twin tails tied with yellow ribbons, green eyes, and visible fangs. She wears a pink variant of the standard academy uniform, featuring detached sleeves, for training and combat. She shares a significant past as Ichika Orimura's second childhood friend. She moved into his neighborhood during fifth grade after Houki Shinonono's family left. Her family ran a Chinese restaurant Ichika frequented, especially when his sister was absent. During middle school, Lingyin endured bullying over her nationality; Ichika defended her multiple times, notably confronting four bullies. This protection sparked her romantic feelings. She later promised him that if she became an excellent cook, he would become her boyfriend, a pledge Ichika misinterpreted as an offer for free meals. Reuniting with Ichika at the academy, Lingyin turns hostile upon realizing he forgot their promise. This disappointment fuels her initial aggression, like challenging him to a class league match in Episode 4. They cooperate to defeat an unmanned IS drone, a Golem, though Ichika is injured. Lingyin watches over his recovery but denies deeper meaning behind their promise. Her impulsive nature surfaces in situations involving other girls; in Episode 8, discovering Ichika bathed with Charlotte (who presented as male), she attempts to attack him with her Shenlong's Ryuhow, an intervention halted by Laura Bodewig. Lingyin displays energetic and competitive traits but is prone to jealousy regarding Ichika's interactions with other female pilots. This jealousy manifests during group activities, like a beach episode where she clings to Ichika and challenges him to races. She reacts aggressively to remarks about her small bust size. She also exhibits a lewd imagination involving Ichika, sometimes confusing these fantasies with reality. In the OVA "Sextet of Burning Love," Lingyin competes with other heroines for the lead role opposite Ichika in a school festival play adaptation of "Cinderella," highlighting her persistent rivalry and determination to capture his attention. Lingyin's ideal world, explored during the World Purge incident, reflects her desire to revisit their middle school years in a romantic relationship with Ichika, underscoring her attachment to their shared past. Her combat skills emphasize close-range proficiency, including partial IS deployments for rapid defense. Outside battle, her culinary expertise stems from her family's restaurant. Though Class Representative for Class Two, she frequently involves herself in Class One activities like training and field trips. Her character development centers on reconciling her childhood affection with Ichika's obliviousness and navigating academy rivalries.