After a while, Mutsumi moves to Tokyo, and the three begin to study together.
During this period, Naru becomes convinced that Mutsumi is Keitarō's promised girl, but Mutsumi states that she made a childhood promise with Naru, not Keitarō.
As Keitarō is about to leave, Naru finally confesses her feelings to him at the airport and decides to wait for him to return.
When Keitarō returns, he and Naru finally begin to express their feelings for each other.
As the two of them grow closer through their studies, and after Keitarō accidentally reads a small section of Naru's diary, he becomes increasingly convinced that Naru may be the girl with whom he made the promise.
On the second day of the Tokyo University exam, Keitarō asks Naru about the promise and is stunned when she tells him he is mistaken.
Around six months before the start of serialization, character designs were still going through several revisions before being settled upon.
Several characters underwent complete redesigns and name changes.
After learning of this, Naru chases after him without checking her exam results either, and they are followed by the rest of the residents of Hinata House who announce that Keitarō and Naru both passed the exams along with Mutsumi.
Both anime and manga have received numerous industry awards in Japan and North America, as well as praise from critics.
The story is a shōnen comedy that takes place in the Kanagawa Prefecture, and centers on Keitarō Urashima and his attempts to fulfill a childhood promise that he made with a girl to enter Tokyo University together.
The anime series, special, and OVA were licensed for release in North America by Bandai Entertainment.
In July 2007, the license was acquired by Funimation, who released a boxset of the television series in February 2009.