It's immediately available at the start of the game and can be purchased from the Edit Costumes Shop. Like all the wearable outfits in the game, it has four variant colors: white, jet black, hot pink, and green.
As the name might imply: the swimsuit's function is show off as much as the character's flesh as possible, while covering just enough to allow them to remain "presentable". It's an ultra-skimpy two piece: comprised of an extremely small string bikini that barely manages to keep the wrestler's figure contained when it's worn by one of the girls.The bottom piece consists of a tiny (bullet-shaped) triangular segment, with a little ribbon in the front. Narrow strings run up high along the hips, then plung down to meet just below the base of the spine in the back, adorned with a larger ribbon, and then "vanishes" into the valley of her backside to create an effect similar to a G-String style bikini (though far more extreme).
The top piece is composed of two similarly small triangular segments set over the center of the breasts. A central string runs between the large gap in the front (across her cleavage) and is tied up in the back. The tops of the front segments are adorned wih small ribbons, and a single length of string comes up from the tips of the segments, and hoops around the neck to hold the top in place.
The Sexy Swimsuit is absurdly impractical as an outfit, let alone as something to be worn in the ring. Though it's obvious that the lack of functionality is deliberate, as the swimsuit was clearly designed to show off the wearer's figure as much as possible. Like the other edit swimsuits, it doesn't include footware, so it allows the the character to fight barefoot in matches.