fusou (swimsuit mode) (kancolle)
The swimsuit official alternate costume of Kantai Collection's Fusou, as seen in post #2584188.
It consists of a casual white one-piece swimsuit worn with a see-through green shawl and a green sarong with floral print, plus red sandals and a 356 mm twin gun mount strapped to waist-level.
This tag implicates fusou_(kancolle) (learn more).