Episode 1: Yuki's Trouble
On the first day of high school, Yuki is not perfectly happy as she failed to get the highest score at the entrance examination. Although she does not show her desire, she wants to be the center of attention always. The honor belongs to her classmate, Arima. Yuki feels strong rivalry to Arima. She beats him at the mid-term exam. To her surprise, Arima congratulates her achievement heartily. One day, Arima tells her that he wants to “go steady” with her. Yuki bluntly refuses his proposal. Then, she accidentally reveals her true desire and is terrified by her mistake.
Episode 2: Hidden Feeling
Knowing Arima found what she actually is, Yuki has to help him for school jobs. Seeing him during and after the class everyday, Yuki is annoyed as she feels she becomes attached to him. She is irritated and tries to deny the change of her feelings toward Arima. Arima always looks friendly and tender.
Episode 3: Arima's Worry
Arima has his own trouble, too. He is feared when he finds Yuki's real personality. He, too, wants to be the center of attention and plays a “nice guy.” Arima confesses it to Yuki. Now, they understand each other and Yuki is aware she is in love with Arima.
Episode 4: First Love
Yuki and Arima promise to each other that they stop “playing nice guys.” Yet, Yuki still hesitates to tell she loves him. She avoids him as she is afraid of being hurt. Yuki's young twin sisters cheer her up. Finally Yuki decides to tell Arima what she really feels on him. Good luck, Yuki!!
Episode 5: Daily Labyrinth
After so many tears and frustration, Yuki and Arima become steady friends to each other. However, both of them are too busy to have time to meet because of preparation for School Sport Day. And after the School Sport Day, a handsome boy, Hideaki Asaba, from Class 1F approaches Arima in a strong defiant mood. Being Arima's girlfriend, Yuki wants to be friends with Asaba. However, Asaba insults her at the first time they meet. He even says Arima will break up with her soon!. Outraged, Yuki declares war against Asaba!
Episode 6: Your Voice changed me.
Because of lack of for meeting each other, and the failure of their fisrt date, Arima and Yuki date frequently afterwards. However, as Arima gets to know Yuki more and more, he becomes more worthless because he's still hiding his true feelings. He starts to question his relationship with Yuki. A thunderstorm one day traps Yuki and Arima after school. They eventually have a chance to tell each other their innermost feelings.
Episode 7: The obstacle between him and her
The final exam are released. The results of Yuki and Arima are terrible. Although they don't care, their teachers are so furious about their results, and ‘suggest' to them that they end their relationship. Yuki and Arima react with anger. The teachers decide to meet their parents to separate them! Good luck to Yuki and Arima!
Episode 8: A memorable day for Yuki
One day not long before Summer vacation, Yuki goes to play at Arima's house. It's the first time they've been alone there. As a test of distance between them, they have their second kiss and Yuki feels even more strongly for him than she did before.
Episode 9: Isolation in the class
Yuki decides to be her real self, but her classmate still treat her as a visitor from outside. The other girls mistrust her and spread rumors in the wake of her parents being called in on account of her falling grades, as well as her getting close not only with Arima and also with Asaba. In the midst of all this, Masahide Isawa, who detects a change in Yuki some time ago, takes advantage of the girls' antagonism toward Yuki to take control of them. And what will Yuki do when these moves finally lead to action?
Episode 10: It all begins now.
Another old friend of Arima's, Tsubasa Shibahime, giving her the evil eye as well. Yuki is hemmed in on all sides. With no intention of giving into these assaults, however, she instead spends carefree days with Arima and Asaba. She even turns aside Tsubasa's escalating attacks as if they were mere jokes. Hearing all of this, Azusa , a friend of Tsubasa's joins Aya and Rika in declaring friendship for Yuki, thus abruptly drawing her into their group.
Episode 11: Summer Holidays begin
All sorts of thins have happened in the currently ending school term. Arima tells Yuki that he won't be bale to see her for a while because he'll be taking part in the upcoming Kendo tournament.
Without Arima, Yuki finds herself spending summer vacation with female friends for the first time in her life. She puts a bold face on it, but, Tsubasa acts very strangely.
Episode 12: Where is Happiness?
Tsubasa opposed to her father's remarriage, declares that she will stay at Yuki's house instead of going home. Yuki is confused, but finally Tsubasa and Maho end up staying at the Miyazawa house. A phone call from Azusa brings Tsubasa's father and his new fiancée to the house.
Episode 13: Subjective Happiness
Tsubasa opposed to her father's remarriage, but soon relizes that her opinions carry no weight, So, she gives in and agrees to meet her stepbrother-to-be, who turns out to be a blond punk rocker named Kazuma. His remarks burn Tsubasa and everything goes right to hell! Later, they meet by chance in the street, with very different results. They realize they're the same kind of child brought up by a single parent with similar background. Tsubasa eventually accepts Kazuma and hence, Hiromi, the stepmother.