This character is kind of a mix of ever trait that makes you go "you go girl" and every trait that makes you go "Whaaaaaat?"
At the very beginning, we are introduced to a girl who has seemingly given up everything to make a single man happy... a man who hardly even bothers to come home at all. She, being of high school age, but not attending high school, because she is trying to work several jobs at the same time, overhears "her man" one day, telling a lover(?) that he thinks of Kyoko as nothing more than a tool to be used. Instead of becoming depressed and running away to evaluate her life like many manga girls do, Kyoko confronts him and vows reveange. He, being a famous music artist could only be touched by the fame of another person in the entertainment industry. And that is how this story comes about.
Kyoko, a shy, soft-spoken person in the beginning, changes everything about herself... her hair, her clothing, her reasons, and quite a bit of her personality too. She bounces back and persists when no one else would. That persistence lands her a spot in a famous company that handles a large part of entertainment affairs in Japan. She, however, has to climb from the bottom to get what she wants. She is put in a special section to learn to help and be loved by others. Perhaps, the most critical part of her character's development comes when she meets the extremely famous actor, Ren. At first, its quite easy to say that Ren hates her completely. He makes her life quite difficult. But a true turning point in their relationship is when he recognizes her as an amateur actor worthy of his skills. This happens right after she has fractured a bone in her leg, making it almost impossible for her to walk. Yet, still, she pushes through her pain to act a role that was lent to her on a pure whim. After keeping up with Ren in his acting, and him disappearing from her sight, Kyoko actually lost consciousness. The real kicker though, is that Ren at this point still hates her.
Her greatest trait perhaps is that she learns fast. She learned fast not to trust Ren or his intentions. She also learned how to act and improvise. Upon meeting and befriending Moko (Kyoko's first female friend), they soon had to do an improv for a commercial audition. The last round of this improv, Kyoko's idea was stolen by a group that performed right before her. In just seconds, Kyoko managed to almost completely rewrite her improv idea and make it entirely better than anyone else's. Another measure of her true ability was when she was asked to act out a character of an older sister that hated her younger sister for killing a parent (accidentally). She deviated from the scrip, but always forced the other person to keep going, eventually returning to the script herself. Halfway through, she was even interrupted by Maria and had to finish acting by convincing the younger girl that her own mother's death wasn't actually her fault.
It was also around this time that she got a job to be Ren's fill-in manager. Ren, not trusting her, took on most of the duties himself, until his health went down hill. She tried her best to please him until he really became ill. It was then that her determination switch turned on. A great show of this determination was when she had disappeared to buy things for his cold. When she returned, it was just in time to realize that he was about to pass out from fever. So, with several enormous bags of groceries in her hands, she used her head (literally) to steady Ren's falling body. She then spent an entire night taking care of him and cooking for him, not sleeping a wink (all this going on while she was studying feverishly for high school entrance exams). And the next day, while Ren suffered terribly, trying to remember his lines in private (and couldn't), Kyoko hid herself and started playing the role of the person he would be talking to. The days that he was sick were also a turning point. For the first time, Kyoko could almost call him a friend. He even called to thank her when it was all over.
From here, though, things get more complicated with her character. Her enemy, Sho (the boy she swore revenge on) started appearing in her life again. It also didn't help that her first real intro to fame was in his music video. Her ability to get through that with a professional attitude was absolutely astonishing, especially since, every time prior to that occasion, she went into killer mode even at the mention of his name.
Audaciously, she was also given the part of Bo. A large chicken that appears regularly in a TV show (kind of like a late night talk show). With this character, she has dissed Sho, insulted Ren, and given him advice and guidance that otherwise could not have been offered by her in person.
Another critical element was when she was asked to play a role in the drama Dark Moon. Her role was opposing the other characters, but it was perhaps the reason why she and Ren became so close. He in fact was offered the starring role in the same drama. With Ren's advances, because her heart was so closed off, she often shrunk back in fear until she realized that the way he looked at her was actually not one of hate at all.
Rather than backing down to people that oppose her, she pipes up and fights. This, however, is only usually true until Ren enters the picture. Ren, who at this point has already fallen in love with Kyoko, often protects her. It seems she understands this, so she usually declines much more to protect herself when he is present.
Her ability to warm people up to her and beat them down when they are being full of themselves is also quite interesting. Though it may not look it, she has an extreme amount of intelligence. She knows how to turn the blackmail of rich child into complete understanding for the person he's blackmailing, and keep him on a leash while she's at it. She knows how to change people's feelings completely, and not even try to.
However, even with all her praises, she's also oblivious to love. While it seems she actually feels it herself, or at least a much deeper connection to Ren than anyone else... She doesn't acknowledge it. Her lack of experience with affection make her head spin when she receives it. But her background makes her able to endure situations that others would run screaming from. For instance, there's a time when she has to stay with Ren for a while in several hotels and gets worried that he's taking too long in the shower. She barges in, only to realize that he is in fact nude and still taking a shower. Instead of running from the room, she stares at him, he (in character) asks if she wants to join him, and she answers back with a smile (in character) that she would love to if she weren't making dinner. She then calmly walks out of the bathroom...
She also feels fear though. In a similar instance, she was unknowingly sent to test Ren's character. When she found him, he was playing the part of a cold-blooded killer and chain-smoker, sitting on a bench by himself. She recognized him, but was scared out of her wits when he glared at her and knocked her down. Later, when he pulled her into an alley, she curled into a ball and shouted apologies until Ren started stroking her hair and telling her he meant her no harm.
All in all, Kyoko is a character with many demons in her past. Her father died, and her mother completely ignored her. Her friend "Corn" (who actually was Ren) was her only real comfort to her tears at the time. Her childhood friend Sho betrayed her heart and her trust, leaving behind only her hatred for him. She's still completely taken in by fairy tales, and loves the fantastical rather than the logical. She fights when she needs to fight, but her most potent weapon is her mind. Kyoko is perhaps one of the few really likable, strong female characters in manga to date.