Young adults Sumiko Miyagawa and Koji Kamiya face many hardships before becoming committed lovers. In high school, Sumiko attempted suicide, only to be stopped by her childhood rival, Koji Kamiya. The two have always competed, whether it was for better grades, main leads in school plays, or even the first to get to the cafeteria for lunch. The two were well-known in school for their acting skills, as well as the fact that they have attended the same schools together since primary school. Despite this, they have a soft spot for each other and often stick up for one another, having known each other for nearly their whole lives. Koji tends to playfully flirt with Sumiko, however she takes this as him playing with her feelings and trying to toy with her, having been warned that he is a no-good-playboy. But one day, an opportunity for them to play as main leads together in a movie, based off a book named "Destined to be With You" changes their lives forever.