Kaon is a young petite girl with very short light-coloured hair and also round light-coloured eyes with long eyelashes. She is usually seen wearing her Miyabigaoka school uniform. Her grandfather is a famous national toy maker, and she always carries a teddy bear made by her mother around with her. Her teddy bear's name is Edward.
Kaon expresses an arrogant and cruelly playful streak towards though she looks down on. Kaon is also stubborn, arrogant and straightforward as she isn't afraid to voice her mind. She is conceited and sometimes even malicious . Kaon easily gets annoyed and seems to like making jokes of bad taste. However, her attempt to upset Misaki by lying about being Takumi's fiancee abruptly grows awry when Misaki dismisses it and mockingly pities her by listing all of Takumi's negative traits. As a reply, Kaon smiles and comments that such arrongance makes her happy and that she's excited over this "declaration of war".
As Takumi Usui first enters Class 3-A and sees the Elite Group waiting for him, Kaon quickly speaks to him,
saying he kept them waiting. When she sees Hirofumi Koganei with Takumi, having followed him there, Kaon quickly comments that she didn't know Takumi had friends and asks him about his family background. Kaon is identified to be part of the Elite Group at Miyabigaoka, a group of students who have very rich and powerful families. The Elite Group is asked by Tora Igarashi, Miyabigaoka's Student Council President, to befriend Takumi when he arrives at the school. As Takumi receives a call on his phone, Kaon stands perplexed with the rest of the group as she hears a voice shout at Takumi. As the talk between the two gets even mushier, Kaon continues listening with a surprised face. She soon recognizes the voice as Misaki Ayuzawa and asks to speak with her
Upon taking the phone from Takumi, Kaon starts talking to Misaki, calling her "Maid-san" and tells her that Takumi cherishes her a great deal but tells her that the pain of separation is inevitable. As she begins to introduce herself as his fiancee, Tomu watches in confusion, commenting that his sister is making a bad joke, to which she gestures for him to be quiet. However, Misaki soon talks to Kaon, telling her Takumi is perverted, hard to figure out, rude and crafty. As Kaon tries asking why she'd say such things, Misaki retorts that Takumi is hers and nothing will keep them apart. To this, Kaon smiles and accepts Misaki's challenge.
While Tomu tries to get Takumi to talk, Kaon grows angry as the latter is unresponsive, only to be calmed down by Tomu. Later, Kaon recounts Tomu's explanations to her that by doing a favor for President Igarashi, a member of the Igarashi family, it will be beneficial for their family. As she angrily comments on the difficult nature of the task, Ichitarō gets in on their conversation, which Kaon is angered by due to his computer-responses until Tomu states they've arrived at their destination: Maid Latte. Perplexed, Kaon is told that though they're in a maid café, the maids don't dress as maids all year around. As she grows angry with the way Ichitarō explains things, he begins getting more talkative, resulting in her slapping him. Though this doesn't slow him down much, as Tomu reminds her of his talkative nature.
Later, Kaon attends the celebration party for Takumi's birthday. As he is riding a horse and everyone is impressed by it, Kaon comments that they have bad taste as she doesn't see anything good at Takumi. As she turns back to leave, she bumps into Misaki (dressed as a guy) and blushes. Suprised, Ichitarō comments that she's sparkling and Tomu says that he doesn't even know what he is supposed to say about it. Kaon also makes a brief appearance when Takumi and Misaki visit the Miyabigaoka High. They spot Kaon walking with the other Miyabigaoka's Elite Group members.Later, when Misaki decides to head to Britain, Yi Hua Li along with the other members of Miyabigaoka Elite Group appear in order to teach Misaki how to converse in
english, the manners of the high society, cultural knowledge of Britain and horse riding. Upon seeing Misaki dancing with Ichitaro and Tora laughing at them, Kaon comments that it's her first time seeing Tora so happy. Then she asks if there's any meaning to this, reffering to Misaki's attempt of learning how to dance. Some time after, while Misaki is being made up by Tenryū, Yi Hua Li and Kaon are trying to review her about the basics famous shops. However, Kaon figures out they can't start as Tenryū puts lipstick on her. When Misaki is ready and doesn't aswer their questions, Kaon says that her general knowledge is worse than she [Kaon] thought.
Misaki replies that even if it's natural to enter the shops in a department store for rich people, she has never entered one. Kaon is very suprised and asks her if there is such a thing. Then Kaon says that she's going to have dinner with her grandfathers and leaves. However, she along her twin brother and Ichitaro come back, interrupting Misaki and Tora, to inform them about a news piece in the foreign celebrity gossip magazine. It is about Takumi as the charming son of the noble making an appearance and they must stalk, aka paparazzi, him. As Tora explains Gerald's plan, the others start talking about Takumi, and Kaon claims that it's impossible to be friends with him. She also states that she hates him.
Kaon also made an appearance when Tenryū is preparing Misaki for New Year's Eve. While Misaki is screaming, she comments that they are a bunch of noisy people. Suzuna thanks the others for their help. Kaon says that they didn’t help her. After giving them some snacks, Suzuna asks for another favor. Soon, Kaon and her twin brother are driving Misaki to some other place. At some point, after commenting on Suzuna, Kaon says to Misaki that she have been pretty quiet during their drive and also that she should be grateful for sending her there.
As twins, Tomu and Kaon spend all their time together and are never shown to be without one another along with Ichitarō. He is often the one to restrain her when she becomes enraged, using headphones to play music that puts her into a trance. Tomu often teases her about her personality and tries to be the cool head to Kaon’s quick temperament. They both bear the burden of their family toy industry yet Kaon takes this responsibility more seriously than Tomu, who admits to lacking a competitive spirit.
Ichitarō, Kaon and Tomu are childhood friends and often appear together as a trio. His motor-mouth habits often irritated the two until Kaon forced him to stop verbally speaking and restrained him to talking through typed messages. He takes great pleasure is tormenting Kaon with sarcastic remarks and overwhelming her with his speeches. Ichitarō and Tomu often gang up to mock Kaon for her violent habits and expresses shock at her brief infatuation with a charming butler at Takumi’s birthday party.
Kaon hates Takumi for no reason, as she repeatedly states it. She doesn't see anything good about him and considers him an impossible guy. Kaon also states that it's impossible to be friend with him. She doesn't understand how people can praise his qualities. Moreover, she considers that everyone that praises his qualities have bad taste.
At first, Kaon showed excitement to battle against Misaki and proceeded to mock her for her maid job which she found distasteful and quickly grew frustrated as Misaki sidestepped her taunting. As they continue to interact, she seems to gain some respect for the girl, though she enjoys tormenting her during her training to journey to England. Kaon is quickly smitten by a cross-dressing Misaki during Takumi’s birthday event, though remains unaware of her true identity. She is shocked by Misaki’s lack of knowledge pertaining to things she views as common knowledge among her upper-class peer group.
- (about Misaki Ayuzawa) "How nice. Such arrongance makes me happy. A declaration of war: I'm extremely excited."
- (about Takumi Usui) "It's impossible to be friends with him. I hate him. That type of person it's naturally impossible for me!"
- (Kaon's reaction about people's opinions about Takumi Usui) "I can't believe this, they have bad taste! I don't see anything good about that guy!"
- Her first name Kaon is an unstable meson produced as the result of a high-energy particle collision.
- Her last name, Umekōji, means "plum malt".
|Tora Igarashi • Kanade Maki|
|Hirofumi Koganei • Chiyo|
|Kaon Umekōji • Tomu Umekōji • Ichitarō Tomikōji • Tenryū Arashiyama • Yi Hua Li|