Protagonist Shinji Aratani is a man who lost everything around him—successful career, family, and friends—due to a twist of fate. His current job title is Chief of Registry Supervision Division of Ministry of Justice. Colleagues in other divisions look down on the Division saying nobody cares about their job and it's unneeded. But what they don't know is that the Division's true duty is to accomplish the top-secret mission from Parliamentary Secretary of Justice to "isolate time travelers in a special residential district and keep them under a close watch." In the near future, it's expected that time machine will be invented and there will be time travelers, each with their own purpose, coming back from the future to the present time. Registry Supervision Division was newly established in order to not let these time travelers change or affect the present and also to prevent big confusion from happening when the existence of time travelers gets revealed.