Little is known about what actually happened to this unit. Haruto told Ibara that one female member suddenly passed away (experiences "sudden death" ) after arriving at Tokyo and the other two male comitted suicides. All of the three dead bodies are buried at the Aoyama Cemetery by the members of the Cleaning Unit.
It was revealed by Setsuna Itami that the real Setsuna Itami (Dr.Coppelius's daughter) had a small amount of genetic material preserved. "We" (she and the unknown female member of this unit) was mass produced from that as imitations (clones). But since the more DNA is replicated, the more it deteriorates, which is the reason for the sudden deaths of the Coppelion - this unit's unknown female's and all other Setsuna imitations' death.