Same as the "DCU (DeepCrimeUnit)" specialization in the underwater organization "DCU (DeepCrimeUnit)" and the stage of the オリジナルドラマ.ドラマのstage となるのは, coast guard 庁に newly established されたDCU というUnderwater incident やaccident のinvestigation を行 うスペシャリストCollection. DCU's abbreviation of DeepCrimeUnit (Diving Special Investigation Team), its mission, the police's investigation of the sea waters, the difficulty of the investigation, and the danger of the rivers and lakes across Japan.あらゆるsubmerge in the water It is proved that the incident has been resolved. "Unresolved incidents in the water are revealed" が、　　　のミッションだ.