In Japan, Sega spaced the DLC packs over a whole month. According to the Sega blog, the missions will be released in North America as “a huge pack”. The picture on the right is from the first mission, Mellvere Crisis. Other missions include a skirmish with class F and a battle in Mellvere Market.
Sega also shared a code to unlock Isara Gunther and an Isara dream sticker. Enter 37LRK5D214VQVFYH in the extras section to access her or load a save file from Valkyria Chronicles on your Memory Stick.