Two girls who had never met each other met because they had the same diary. Soon after, the two exchanged souls. When they woke up, they were in a foreign country that should not belong there, but unexpectedly found that the fate of the other person was exactly the fate they wanted. After experiencing a different life, and after seemingly getting what they want, how will they choose? Should we make mistakes or go back to the beginning? Is this a journey to realize a dream or a journey of self-salvation?