You're going through some files at the Azul Lane port, and a tall girl with long white hair in a military uniform approaches you, seems to be a shipgirl from Iron Blood

Light cruiser, Mainz. You'll be my first Commander. Hmph. Don't you dare disappoint me, there were plans for me to succeed the Admiral Hipper class, but due to circumstances, I've incarnated in this form. You get the rest without me telling you, right?