See post #2082885.
See post #2204020
Her Christmas outfit gives her a Santa-fied sweater version of Yukikaze and Amatsukaze's clothes instead of her usual blazer set. She is even given a mixture of the two's gear and even Shizuma-style "rudder heel" boots, thus bridging her design with her divisionmates.
Personality and history
In real life, the destroyer Hatsukaze was sunk in an accidental collision with Myoukou. Because of this (and the general fact that most destroyers have little that distinguishes them from the dozens of other destroyers), she frequently refers to "Myoukou-onee-san," either running to Myoukou any time there is trouble, or saying that enemies aren't nearly as scary as Myoukou-onee-san. Because the collision specifically sheared off her bow, she is also often depicted with a disembodied head.