Main heroines are two girls who have special memory disorder due to some accident. Every few hours there is such time for them that they can't remember afterwards. Memory works in that way that they can't remember anything during that time. In other words, whatever they do during that time, they forget. Knowing this, they work together to compensate for each other's lack of memory.

In the early stages the story is full of gaps, and the whole picture is not perceived. Protagonists continue to suffer from insidious bullying without understanding how they got into this or that situation. However, as game progresses, different viewpoints are given, and "memories" start to gather together. The whole picture becomes clear.