Zara is a reward for the final map of this winter event. It can be unlocked under two conditions: 1. You clear the map before, with a sortie quest on in your quest log. 2. AFTER you cleared aforementioned quest, a new quest open, tasking you to send girls on an 15mins expedition that can be seen in the event exclusive expedition quest.
When the expedition is cleared, you do see Zara among the returning girls . Yet, she will not be in your fleet until you cleared the final map you just unlocked. The final map is quite long because you need to empty the supply bar with a combined transport fleet (have fun playing with gimped shipgirls loaded with drums in a map with a gauntlet of two trollsubs nodes and one light Abyssal fleet that can be problematic if your girls failed to kill them). Then you can send your Hotels, Nagatos, Bismarck and the Lesbian Duo to clear the boss gauge and finish the godamned map. And onward to E4 if you missed any of the girl you wanted like Graf Zeppelin, Prinz Eugen, Amagi or Akizuki. And welcome Zara who just played hide and seek all over the base AND E3 map!
She was having a tiramisu over there until just a moment ago, but...She said she was heading off to the back field.Hey, you got any idea what Zara's up to?
I've not seen hide or hair of her since the Naval Review.Zara? She was doing wine-tasting with us here until just a moment ago, but...She said she had some business in the wine cellar.nhnm... Zara?She was in here filching pasta until just a moment ago, but...I get the feeling that she said she wanted to eat some of Mamiya's snacks or something...What's wrong, Nagato? You've got quite the face going on!She said she was going to make pizza in the kitchen!We were taking a nap together until just a moment ago, but...Oh my... you're like ships in the night, aren't you?Zara-san, you say?