She is voiced by Asami Shimoda in the Japanese version of the anime, and by Hilary Haag in the English version of the anime.
Rin takes the appearance of a young teenage girl. She has light brown hair tied into twin tails, with a yellow ribbon at both sides. Compared to the other IS heroines (sans Laura), she is quite petite. She has green eyes and usually wears her IS Academy uniform Her uniform seems be specifically altered for her as her sleeves are detached from the uniform.
In all of her appearances, she often appears smiling with an exposed fang, which is why many fans misspell her name as "Fang Lingyin".
For her IS practices and battles, she wears a pink version of the training uniform.
Rin is depicted as a very energetic girl with a slight competitive streak. This is seen when Houki and Cecilia were arguing with Linying about her relationship with Ichika. She effectively answers them while hinting that she has an advantage over them (e.g. when Houki said that she has eaten and slept with Ichika when they were kids, Lingying said that he has been coming over to her place to do the same when they were in grade school, though Ichika is quick to clarify by saying he ate at the restaurant her family owns).
In her middle school year, Rin was usually the target for pranks due to her nationality. However, Ichika helped protect her from these situations (e.g. when he protected her from four school bullies). Because of this, she developed romantic interests for him and made him promise that if she became an excellent cook, he would become her boyfriend. When she meets Ichika again at IS Academy she becomes disappointed and extremely hostile to him because he had forgotten the details of the promise. When he asks what she means, she just says that it means she will give him free meals, hoping he would not understand the meaning, which is technically a lie.
Lingyin is very impulsive and irresponsible, as she always acts without thinking about her action or the problems with them, which is made worse by the fact that she has a personal IS. This often causes headaches for her superiors in China because of the trouble she usually causes as a IS Representative Candidate. She rarely acknowledges her actions as her fault (which they are) but instead's blames someone else (mainly Ichika).
She can become extremely jealous when there are other girls around Ichika who are trying to get his attention, to the point of showing the stereotypical lifeless eyes of a "yandere" girlfriend (this trait is shared with Cecilia in episode 9 and at the end of episode 12). This trait is also showed at the end of episode 8, when Charlotterevealed that she was a girl. Rin crashed into the classroom and was immediately about to shoot Ichika with her Shenlong's Ryuhow without giving him time to deploy his own IS. Similar to Houki as she's also his childhood friend, Rin's cruelty towards Ichika hinders her from getting closer to him (meaner than Houki to be precise). However the case may be, Lingyin highly expected Ichika to notice how she feel about him. But she keep her true feelings as a secret. Despite being the same age as Ichika, Lingyin's too immature to give him a chance to bond with her, which also hinders her from getting closer to Ichika despite them being childhood friends.
Rin is very sensitive when it comes her bust size. She can become easily enraged when her size is mocked or pointed out by others. Her friends are aware of this and don't talk about it (in the LN, Houki made it a point not to ever' complain about her large breasts in front of her). Strangely, she usually brings up this topic when she starts thinking about it or notice other girls' breasts. In Season 2 Episode 5, she became enraged and jealous when she saw Ichika look at Charlotte's breasts, believing he was only focused on them.
- Rin is very similar to Louise de La Valliere. Both are often very cruel and abusive towards their potential love interest (Ichika Orimura and Saito Hiraga), both have the second smallest chest size out of their love rivals (after Laura Bodewig and Tabitha) and both fly into a rage whenever their chest size is mentioned.