Resized to 85% of original (view original)
Artist's commentary
Yuudachi returns to her original state when her Kai Ni power is exhausted
Yuudachi needs to be regularly charged with the Admiral's power (highly suggestive) to maintain her Kai Ni form, or at least that's setting I just came up with!
Oh, if it isn't Haruna who recently gained Kai Ni, Hello^^
Kai Ni, lit. Second Revision, refers to the second upgrade available to some ship girls in Kantai Collection. It is accompanied by updated art, and generally a significant power boost.