Tenjōin Saki

Saki Tenjouin is the arrogant self-proclaimed queen bee of the school. She is currently in her third-year. Saki consistently tries to defeat Lala in everything, stating there can only be one "queen" in Sainan High. She even tries to seduce Rito to make Lala jealous (despite not loving him), but later, she falls in love with Zastin Deviluke. She once teamed up with Run Elise Jewelria to make Lala look bad in front of Rito and to prove that Saki is the queen of all things.

Appearance
Saki ﻿has gold eyes and light gold hair that's lightly permed in the back and curled into spirals over her shoulders. She also has her hair in two dome shapes on both sides of her head held by red ribbons.

Personality
Saki can be stuck-up and full of herself, and she is quite competitive (mostly to Lala) to try and prove that she is a magnificent person, and even gives herself many different titles as a self proclaim queen. She also has a proverbial laughter that is very stereotypical to her stuck-up personality.

On the other hand, she has a kind side to her, as she saved Aya from bullies and cares for her deeply as one of her closest friends along with Rin. She basically feels competitive towards anyone who might rival her glory, but otherwise, she can be quite courteous and hospitable even towards humble people. To her credit, she does try to earn the love and glory she wishes to receive from people by serving them with her own wealth, such as when she hosted a Christmas party for various people and other students, when she invited classmates to her private beach, and when she served food to her servants. She is very caring towards her friends, and is polite and grateful towards her domestic workers and guardians, showing a great deal of worry for them and never looking down on them as mere servants or commoners.

Rin Kujou
Rin is Saki's bodyguard and friend. Her family has served the Tenjouin family for generations.

Saki considers both Rin and Aya to be her closest friends, to the point that she ran away from home rather than be forced by her father to study abroad without her friends. Rin, on the other hand, while caring for and greatly respecting her, is a little more divided between her loyalty to her Saki-sama and obedience to her family, who serve Saki's family. This was seen when Saki ran away from home, and Rin arrived to bring her back by force rather than support her. Ultimately, Saki did not leave to study abroad, and they were able to remain together.

Recently, Saki noticed Rin's more bashful expression around Rito Yuuki, which she has never expected from Rin for as long as they have known each other. Claiming that she also understand what love is like, Saki is very supportive of Rin's growing feelings, even if it's towards someone like Rito.

Ayako "Aya" Fujisaki
Aya is Saki's close friend. As a child, she was often bullied and Saki protected her. So far, Aya has served little purpose throughout the series besides following and supporting her Saki-sama, whom she idolizes. She has never been seen without accompanying her friends, being something of an extra to their group. But Saki does care greatly for Aya as well as Rin, and wouldn't take the chance to study abroad if it meant leaving her friends.

Being weak-willed and nothing truly remarkable, Aya is perhaps one of the few evidences that the usually arrogant Saki Tenjouin has a good and kinder side towards lesser people.

Lala Satalin Deviluke
Saki considers Lala to be her eternal rival, and goes through any means to prove that she is better than her, even though her plans usually backfire and sometimes ends up naked in the process. Lala remains totally oblivious that Saki holds a competitive grudge against her and considers Saki a good friend of hers.

However Saki was grateful to Lala for helping her at the time she had tried to run away from home.

Zastin
Saki has been in love with Zastin ever since he helped her get her limo out of a small hole on the ground. She was frustrated when she found out that he is Lala's servant. She tries to get closer to him and gain his affections, but with little success. While Zastin is always formal and polite towards her as he is with everyone else, it is unknown how he feels towards her as he seems slightly oblivious to her feelings, and there is little evidence that he has romantic feelings towards her.

Rito Yuuki
At first she tried seducing him to make Lala jealous, but this did not last long. Since then, any and most of her appearances seem to only serve the purpose of being a victim to the perverted mishaps that surround Rito.

Due to her feelings for Zastin, she along with two of close her friends (later just Aya) are the only ones in the female cast who have absolutely no romantic feelings towards Rito  and she gets mad at him whenever he accidentally does something perverted to any of them. In To Love-Ru Darkness Chapter 31, Momo didn't consider her or Aya for her harem plan.

Saki unintentionally showed Rito a warmer side to her when she showed kindness and hospitality to Riko Yuusaki, until Riko's shocking revelation, which only added to Rito's already perverted history around Saki and her friends. Even though she hates him, Rito would still try his best to help her, like when she ran away from home and he allowed her shelter in his home, for which she showed little gratitude toward him.

Despite her general dislike of Rito, she nonetheless supports Rin's recent crush towards him, noting that, of all people, Rito is the first to make Rin feel this way.

Run Elise Jewelria
Because Run also held a grudge against Lala, on one occasion, Saki has teamed up with Run to humiliate Lala, but as always it would ultimately fail and backfire. They don't team up anymore due to Run's busy schedule as an idol and has no more intention in doing so.

Trivia
Saki made a cameo appearance  along with Rin and Aya  in Mayoi Neko Overrun! in ch 3 pg 24.