Eigo is the serious and mature member of Team Hiragi who attended the same middle school as Kaito and Tooru. He is good at observing and analyzing music. He is childhood friends with Rui, and they were often called "Princess" and "Knight". (Source: Wiki)
Izumi is the fashionable and flirty member of Team Hiragi. With a handsome face, he is very popular among women, even taking them out using Shuu's motorcycle. Though he resembles a delinquent, he is actually a caring guy. He is childhood friends with Shuu. (Source: Wiki)
Akane's friend and rival. Student of class 3-B.
One of the dragons of Heaven, a fourteen-year-old schoolgirl descended from the keepers of Mitsumine Jinja, masters of inugami (dog-spirits), Yuzuriha is exceedingly energetic, often diffusing latent tension between Kamui and the rest of the Ten no RyÅ«. Yuzuriha is attended by her own personal inugami, Inuki, who can transform into anything she desires and who only others with occult powers can see. She was teased throughout much of her childhood as her classmates believed Inuki was her imaginary friend. Because of this, Yuzuriha made a vow that she would never fall in love with (or even date) a man who could not see Inuki. However, the first person outside of her family that she meets who can see Inuki is ShiyÅ« Kusanagi—a Dragon of Earth. Yuzuriha falls in love with Kusanagi, regardless of their conflicting fates. In Tsubasa Reservoir Chronicle In Edonis country, she's a player who's paired up with Kusanagi Shiyuu. In Tokyo, she's one of the seven fighters of the Tower faction.
Very young student (10 years old in the beginning) in Nodame's school in Paris. His goal is to be a conductor. In OVA 2, he became 15 years old and is in love with Chiaki's cousin, Yuiko.
Haruka's younger sister, She initially sees both Takayuki and Mitsuki as older siblings until she finds out they have been seeing each other behind Haruka's back. While Haruka is in the hospital, she visits every day since there is no one else that can keep her company, even if Haruka is in a coma. This shows just how much she loves her older sister. She, like Mitsuki, is a powerful swimmer in her own right, but feels as if she can never match Mitsuki. Her intense hatred towards Mitsuki after the accident can be attributed to the feeling of personal betrayal by someone she considered an idol for throwing away her (Mitsuki's) talent and dreams as well as Mitsuki's betrayal of her sister by her sexual relationship with Takayuki. She learns to move on in life and becomes a top swimmer in Japan. (Source: Wikipedia)
Tamaki is also childhood friends with both Konomi and Takaaki the two see her as an older sister. She left them when they were both children, having to go to an all-girls boarding school. Her promise to come back to Takaki in the final year of high school is what prompted her to leave her boarding school. She is very confident and comes from a rich family. She is well versed in traditional Japanese arts and traditions, yet still is a modern girl in her own right. In her group consisting of Konomi, Takaaki and Yuuji (Tamaki's younger brother), she is the strong and dominant personality and is acts as the older-sister figure. She often addresses herself as "Tama-oneechan".