On a certain day, two high school students Mina and Hiromu lost their lives after getting swept up in a traffic accident. In the realm of the dead, they discover that one of them has one more year of "life" left but are unable to find out whose. That precious time is hence divided between the two. They return to their lives, only to head face to face with a cruel reality. Regardless of what the fate that awaits them may be, it will certainly be shocking.