Unofficial biography, made by me. Contains lots of spoilers for the series. I will make a spoiler-free biography soon. Largely incomplete.

Name: Takane Shijou
Age: 23
Birthday: January 1997
Eye Color: Carmine
Location: Kyoto
Hair color: Silver
Favorite color: Silver
Personality: Elegant and refined
Voice Actor: Kana Tsukimori
Debut Episode: Season 1, Episode 1
Nicknames: "Silver Queen" (creators), "Graceful Takane" (Chihaya), "Hoshibito-chan" (Matsu), "Takane-chan" (Akane)
Current status: Alive
Name Meaning: Her first name means noble (貴) and her last name means sound (音). Her last name means four (四) and article (条).

Takane Shijou is a 23 year old young adult who has decided to take in one of her hobbies; creating music. She was already very gifted in playing woodwinds and strings, especially the flute and violin. She used to play on the street as a hobby; however, the director of a small Kyoto orchestra decides to hire Takane as a violinist. She makes her first performance in the orchestra. A 22 year old lady, Azusa Miura, had heard Takane's whole performance. Azusa invites Takane to a tea party. Azusa shows Takane Shijou some of her art pieces, which Takane complemented a lot. Takane Shijou tries making her own art piece, but learned she wasn't as good as Azusa. Azusa wanted to learn from Takane. They agreed to teach each other in their expertise fields, and they become really good friends.

Azusa introduced her to her timid yet kind sister, Matsu. Matsu however hid; she was scared of Takane Shijou (she called her an alien). Azusa eventually convinces Matsu that Takane wasn't an alien, but Matsu was still scared of Takane Shijou. When Takane introduced her to her little sister, Akane, Akane tackled Azusa and then went crazy. Takane told her to calm down, but Akane wouldn't even listen to her big sister this time, making Azusa a little scared of Akane.

Takane eventually meets a teenager named Chihaya Kisaragi; she was very polite. She idolized Takane ever since learning of her existence. Takane called her sweet, and Chihaya even earned a nickname from her, which was "idolmaster." It would change Chihaya's life forever.

In the second season, she meets a rival in the orchestra she was in. Her name was Umi Kousaka, a violist. Umi highly dislikes Takane Shijou, but Takane Shijou wants to be Umi's friend. Umi Kousaka always ranked lower than Takane, and is determined to beat her. Umi still considers her a rival, while Takane Shijou doesn't want to be bothered by her...

On July 29, Takane Shijou gets an email from the local Kyoto hospital, saying that Chihaya had become really ill and was about to die. Takane tried to be as fast as possible, but it was traffic hour, frustrating Takane a little. However, she arrived too late, and Chihaya was already dead. Takane got really angry and blamed the traffic, and started throwing things. She started to bawl; she thought Chihaya was a really nice person, and didn't want to lose her. She was eventually taken out of the hospital by staff. It still hurts her to this day how she was too late to say goodbye to Chihaya...

Facts
Her favorite food is ramen. She eats lots of it, and she has a huge appetite as well. Do not take away her ramen.
She was raised by foster parents, while her sister, Akane, was raised by her biological parents. Takane Shijou gets along with all her parents very well.
She doesn't show much emotion, except for the time when Chihaya Kisaragi died in bed. She started crying loudly, and throwing things, which was very unexpected of Takane Shijou.
She is best friends with Megumi Watanabe, a friend from her childhood. Takane really appreciates the hats that Megumi wears, and sometimes joins her in wearing hats, no matter how strange they are.