Son of a wealthy family and the older of the twin brothers, Yugo, is kidnapped. 20 years later, the younger brother, Keigo, is a detective with the First Investigative Division of the Metropolitan Police Department. Yugo’s kidnapping case was terminated in spite of the fact that it was still unresolved and his whereabouts was unknown, let alone whether he was still alive. When the DNA of the suspect of an attempted murder case Keigo is investigating matches his own, he is convinced that Yugo is alive.