yamashiro (swimsuit mode) (kancolle)
The bikini official alternate costume of Kantai Collection's Yamashiro, as seen in post #2584191.
Her swimsuit consists of a white bikini with a floral print yellow-pink sarong and red shoes, while she carries a 356 mm twin gun mount to her back and attached at waist-level.
See also
This tag implicates yamashiro_(kancolle) (learn more).