Salute
Nagate and Shizuka return to Sidonia where they are heralded as heroes and for their services in the last battle, Nagate, Shizuka, Kunato and En Honoka are promoted to official Guardian pilots. In the occasion, Kunato apologizes to Nagate for his prevoius behavior towards him and Nagate meets Captain Kobayashi, with questions for her about why his grandfather raised him in the underground and why his wounds heal an accelerated rate, but the Captain only asks for him to continue with his good work. After the party, Nagate is approached by Yuhata who asks him to accompany her in a underwater ride and Shizuka and Izana accompany them. However, Yuhata attempts to get alone with Nagate in a batysphere and when the others interfere, Nagate ends up riding alone with Shizuka instead. The two spend some quality time until they are called for another sortie, as a large Gauna is seen approaching Sidonia. Nagate departs to confront the Gauna with Shizuka and wakes up some time later in the hospital, where he learns, much to his horror, that Shizuka was killed in the battle.
Aired 16/05/2014EP 6 - Salute

Knights of Sidonia
It's been a thousand years since the Gauna, a strange alien race with no known method of communication, destroyed the solar system. A portion of humanity managed to escape using enormous "seed ships" like the Sidonia, which have allowed them to maintain the population while drifting through space. Nagate Tanikaze is a young man who has been raised deep in the bowels of the ship. When he goes into training to pilot the huge robotic weapons known as Gardes, Nagate is entrusted with piloting the legendary unit known as Tsugumori. Nagate and his fellow pilots put their lives on the line against the Gauna, in the ultimate battle for the survival of humanity!
(Source: AniDB)