hatsuzuki (swimsuit mode) (kancolle)
The bikini official alternate costume of Kantai Collection's Hatsuzuki. While considered an official costume, it has remained unreleased in the game apart from the 2018 calendar.
Her swimsuit consists of a two-tone one-piece competition swimsuit set in blue/black and white, plus a red-white striped innertube with her name on it.
See also
This tag implicates hatsuzuki_(kancolle) (learn more).