Mikami, Kanji, and Satomi have been friends since they were children, having grown up in the same small town in Ehime Prefecture on the island of Shikoku. Now, all three are in their early 20s and have made their way to Tokyo for different reasons. Kanji is last to arrive, having gotten a new job in Heart Sports' sales department and transferring to the Tokyo office. At work, he meets a vivacious new colleague, Rika, as well as being reunited with his best friends from home—Mikami and Satomi. Mikami is Kanji's best male friend and Satomi is their platonic female friend whom both have had a crush on since high school. The situation becomes more complicated as Kanji sees Mikami forcedly kissing Satomi, which upsets Kanji deeply. But he heals his broken heart by developing strong feelings for Rika, who is energetic, funny, encouraging and caring. However, their relationship is a bit unstable because Kanji is dating her on the rebound, and Rika has been having a (not so) secret affair with her and Kanji's boss, Sendo. The affair is de-emphasized in the TV series, but in the manga, the affair is much more important. Rika gets pregnant with Sendo's child (not shown in the drama version). Meanwhile, Satomi thinks that Mikami was just playing with her when he kissed her, and so she rejects him. He turns to a medical school classmate, Nagasaki, and begins pursuing her. Eventually Kanji realizes Satomi's feelings, and he chooses her over Rika.