The game revolves around the main character's 3 days repeating over and over again, where he is constantly being killed in the third day of the story (in various ways) but magically being brought back to life in the first day to repeat his 3 days. Your goal here is to solve the mystery behind the death of your senpai and also to find the identity of the murderer. [From a forum post by Adellus]

Our protagonist Takahiro Kuroda returns to his hometown, Mahoroba City, after several years. Much to his surprise, the city is now divided in two districts: Mitsurugi and Kagami. The traffic of people who cross the barrier is strictly regulated. Will Takahiro be able to meet again with his childhood friends, whom he promised to see again, despite the troubles the barrier gives?