Realise swimsuits are well-known, but I like the description of these ones:

“It is a full-scale swimming suit costume brand for a maniac.

The real material for swimming suits is used. Although actual swimming can also be used satisfactorily, please keep in mind that a reliance cloth and cups are not attached. It starts from a pattern by an original design, and I am manufacturing by the same process as an actual swimming swimming suit, and sewing.

Since I am using the high-class water resistance material, a lotion play etc. should use in comfort.”

Very fair and very self-explanatory. Such suits are obviously made to turn completely transparent when wet ;-P

Found in these shops: Made in Japan Products and G.H.R.Japan.

See also: Lycra on eBay – interesting finds