Also known as: 木曾改二(水着)
The Bikini Official Alternate Costume of Kantai Collection's Kiso (Kancolle), intended to have been exclusive to her kai ni form. While considered an official costume, it has remained unreleased in the game apart from the 2017 calendar.
Her swimsuit consists of a Black Bikini with white tiger stripes, plus a brown Straw Hat.