Plot Summary: Nanami Takahashi, a 15 year old high school student, falls in love with and begins dating the most popular guy in school, Yano Motoharu. However, their relationship is not easily maintainable. Yano's past, as well as the complex emotions they bring up, make it difficult to be completely honest about how he feels. Caught in the middle are Yuri Yamamoto, the younger sister of Yano's now dead ex-girlfriend, and Takeuchi Masafumi, Yano's best friend. Yuri's past with Yano goes deeper than one might suspect and her feelings run deeper than she portrays in public. Takeuchi cherishes Yano's friendship, but at the same time, he may lose it for someone dear to him. Nanami must search deep inside herself and find her true feelings for Yano while being able to trust and accept Yano's feelings for her as well, deciding if Yano is indeed the one for her or if someone else can provide better solace. Along the way Nanami will get tips from her love infatuated friends, Mizu and Taka.

The anime basically follows through the plot line of the manga until Yano and his mom move, leaving Nanami behind. The story continues with Nanami, 21 years old and in her final year at S Girl's College (since she did not manage to enter J University), and already living in Tokyo. It turns out that she has not seen Yano for consecutively 5 years since the parting at the train station. Half a year into Yano's arriving at Tokyo and he completely cut off all communications with Nanami. The reason to this is unknown at this point, leaving Nanami both heartbroken and confused. It is believed that no one knows what happened to Yano. The story follows on, with Nanami deciding to leave her feelings for Yano behind and begins dating Takeuchi. However, the latter soon confesses that he did meet up with Yano (and was probably the last person to see him) before Yano actually disappeared.

It turns out that ever since moving into Tokyo, Yano ran into a lot of problems such as financial difficulties, finding a place for his dog, Lalami to live in (but managed to do so thanks to a close classmate, Aki, who later falls for him and even meets Nanami in the company they work at), and his mother's health problems. His mother's health deteriorates both mentally and physically (especially after Yano's dead father's wife shows up with the incline to take Yano back with her). Throughout this time, Yano has kept his problems from Nanami, in hope that she can concentrate on her studies. Twice he made the attempt to return to Hokkaido to see her, but failed to do so because of his mother. This is unknown to Nanami, however. Finally, Yano's mother took her own life (note that this takes place around half a year after Yano's arrival at Tokyo). Since the funeral, it is stated that Yano 'completely vanished'. It is shown that he did see Takeuchi around this time, telling the latter that he is leaving Nanami in his care, and that he has decided to give up everything from his past, even those dearest to him. Yano seems to believe that it was his fault that his mother committed suicide, stating that 'I was the one who killed her'.

Roughly half a year later, he made a phone call to Nanami's house which was then picked up by her mother. This too, was not told to Nanami until she was 21 years old. Yano's personality appears to undergo a change. He has since started dating many girls, but states that he "does not treat girls like anything important" anymore. During this whole time, Yamamoto Yuri has not given up on him.

The story continues a year after Nanami realizes the truth, with Aki who now works with Nanami in the same company, suspecting that she may have found Yano. Her suspicions turn out to be correct. However, though Aki finds out that Yano is aware of Nanami's whereabouts and her relationship with Takeuchi, he makes no move to see her. He even states that this is how he wanted it to be. The same goes with Nanami who decides not to meet Yano even after Aki gives her details about his whereabouts and informs her that Yano is currently a designer collaborating with their company. She tearfully admits to Aki that she has no confidence of making a clean break with Yano. It is shown that Yano is now living with Yamamoto Yuri and he also reveals that Nanami is 'different', stating that she will survive even on her own.

On the day of Nanami's birthday, as seen from chapter 50, Takeuchi proposes to her but he got rejected by Nanami. In the latest chapter 51, Nanami resolves to look for Yano. Upon being told that he is going on a trip, she ventures to the airport and sees the back of someone who resembles Yano. She calls out his name in tears, but the scene is left with a cliffhanger. Takeuchi, on the other hand, visits Yano's home and comes face to face with Yamamoto Yuri.