Pieta lives an ordinary life in a world of constant black rain. On her 16th birthday, she experiences a series of unlucky events, yet she remains content as the day continues, having expected that these events would happen. Pieta takes satisfaction from the seemingly normal day in which her friend, Danae, gives her a present at school and she blows out the candles on her cake after returning home to her mother.

For the 1033rd time, the next day is Pieta's birthday once again, and she goes through her daily routine by meeting up with Danae. But unlike the day before, Danae experiences the same awful events Pieta suffered previously. Seeing Pieta's calm anticipation of things, Danae realizes that they are both stuck in a time loop. Pieta is elated that she is no longer alone, although her companion remains in shock. However, little do they know that something very sinister lies within the time loop.