This is a LoHa LoRA! You need the extension!
Why? LoHa have virtually no effect in output art style and they do a lot better with multi-concepts.
Trigger words for V2.20:

<lora:SkinTightv220:0.5>(skin tight, taut clothes, impossible clothes, 1girl)
Works RELLY well on any kind of clothing if you want just the effects!

You can try "impossible clothes", "taut clothes", "form fitting", "covered nipples"(for nipples texture under shirt and nothing for flat round breasts),"puffy nipples", "cleavage", "areola slip", "see-through"(for colored nipples under shirt), "navel" and "midriff"(for short shirt).

Follow the steps in the Model Version notes to reproduce my images.

Sample images generated from multiple models.

All negative embeds should be easy to find. and Prompts should be included in the sample images! Click the little icon in the bottom right to see it.

It learned pretty well how to do covered nipples! Probably capable of using it for any type of shirt if you just want nipples texture.
Could use same tags in negatives to control how it generates.

You might want to add some negatives, for example:
(covered nipples, see-through, navel, midriff, impossible shirt)

It was trained on 170 512x512 images scraped from the internet and 20 epochs using animefull_final.

Danbooru tags generated by Waifu Diffusion 1.4 Tagger and fine tuned for specific details like nipples texture, see-through, and impossible shirt or form fitting.