A Flux LoRA of the 'Tencho'* of the BikinisTokyo.com online store, Kotono.
For those unfamiliar, she models most of the swimwear and lingerie herself, as well as running a YouTube channel where she (sometimes) tries the stuff on. Less so these days as YT has become increasingly prudish - these bikinis are very, very small indeed.
She has possibly the best bottom in the whole of Japan!
*Roughly translates to "store manager"