Shirakami Fubuki's swimsuit skin in Looking Glass of Fact and Fiction, hololive's 2019 collaboration in Azur Lane. See post #3699077 for in-game art.
It consists of a black choker, a white halterneck string bikini top with a front tie and a blue multi-strapped bikini skirt.
This tag implicates shirakami_fubuki (learn more).