A summer vacation day. Main heroine digs up a time capsule buried as a child with two friends. Surprisingly, there is also a fourth person belongings inside the capsule, and none of the three friends have any recollections of that person. They start investigation to find out the shocking truth.

A summer vacation day. Main heroine digs up a time capsule buried as a child with two friends. Surprisingly, there is also a fourth person belongings inside the capsule, and none of the three friends have any recollections of that person. They start investigation to find out the shocking truth.