Darker than Black - Kuro no Keiyakusha: Gaiden (OAV) DVD

After the incidents in Tokyo, Hei and Yin try to bury their past and start a new life, but everywhere they go someone seems to be following them. Unaware to Hei, Yin's current odd behavior appears to be related to a prophecy that might lead to the end of the world.

Gaiden fills the gap between Darker Than Black and Ry≈´sei no Gemini. We are going to find out why Hei was after Yin and what she is exactly.