During Yuu and his friends' stay in Tokyo, a shooting incident took place. The murder weapon used in the incident was the same type of gun that was buried in a time capsule seven years ago. The children cooperate with each other to clear their own suspicions, and at times, suspect each other.
The story takes a sharp turn from the conclusion of ..Time Capsule - Haru'', a multi-site suspense adventure!

[Translated from developer's site]