Yume no Mirai Nikki

Our protagonist, Yume, has a daily routine of keeping a diary without fail. But one day, she falls asleep while writing in her diary. The next morning, when she wakes up, she finds that her diary somehow contains entries that she didn't write down... This puzzles Yume. But by the end of the day, she realizes that everything written in the diary actually happened in real life. "Does this diary have precognitive powers...?" The diary predicts that her childhood friend, Saichi, will be involved in a traffic accident. "What should I do...?" Yume worries alone, but what action will she take to protect Saichi?! (Source: Shogakukan, translated) Note: Includes three extra chapters.