Takes part a while after Ikki accepts Simca's offer to become the new leader of Genesis. Shows the Battle between Kogarasumaru and Potemkine. Episode takes place between 21 and 22 of the Main series
Special episode included in the last of the nine Blu-ray/DVD volumes. The story is set a few months after the last scene of the television series. On a calm day in Akihabara, Okabe and the other laboratory members are invited by Feyris to go to America. Mayuri and the rest are planning to reunite with Kurisu, who had come back to an American laboratory. A few days later, Okabe's mad scientist persona Hououin Kyouma arrives alone at the airport in Los Angeles, where he may be taking the first step to leading the world into chaos.
Takes part a while after Ikki accepts Simca's offer to become the new leader of Genesis. Shows the Battle between Kogarasumaru and Potemkine. Episode takes place between 21 and 22 of the Main series 
Special included in BD vol. 5.
Episode 13 of Denpa Onna to Seishun Otoko released on Blu-ray & DVD.
A recap of season 1.
Extra episode included on BD/DVD vol. 6; effectively episode 13.
Special episode included in the last of the nine Blu-ray/DVD volumes. The story is set a few months after the last scene of the television series. On a calm day in Akihabara, Okabe and the other laboratory members are invited by Feyris to go to America. Mayuri and the rest are planning to reunite with Kurisu, who had come back to an American laboratory. A few days later, Okabe's mad scientist persona Hououin Kyouma arrives alone at the airport in Los Angeles, where he may be taking the first step to leading the world into chaos.
Unaired episode 13 bundled with 6th Volume of DVD/Blu-rays.