Naho immediately feels a connection to the new boy who has transferred to her class. Kakeru is calm, kind, and seems to like Naho as well. But their relationship gets thrown for a loop when Naho receives a letter from the future. The letter explains that Kakeru will die unless Naho does exactly as the letter says. But changing fate is no easy task. When the letter starts to get things wrong, Naho worries that she will still lose Kakeru forever. Luckily, Naho has her friends to back her up. Not only do they want to see Naho and Kakeru get together, they also have time-traveling letters of their own...