All 3 models: Mikoto, Tooru, Yuujirou can and will add small breasts and depending on the model, normal breasts. Unfortunately I'm terrible at regulating this. You can add "1boy" or even a LORA that removes her breasts.

1.0 - Trained from 20 to 40 images, I believe it was reasonable.

1.0 [Crossdressing] - I believe it looks good, but unfortunately LORA tends to make the breasts feminine, adding volume. If there is a LORA that flattens more, that would be good.

1.1 [adaptive] - In this version I "toquei o foda-se" (Brazilian expression), and left it feminine, since I'm incompetent anyway. You can have a flat chest, normal breasts, or large breasts. In this version, it is more compatible with LORAS that add penises, some work well, others not so well.

Commonly used models:

Hassaku: https://civitai.com/models/2583/hassaku-hentai-model

Hardcore Hentai: https://civitai.com/models/136054/hardcore-hentai-13

Noosphere: https://civitai.com/models/36538/noosphere

Matrix Hentai: (Unavailable)

Models are trained from Hassaku or Anything V5.

If you're out of ideas for prompts, how about 13886 prompts? This is what I have for you

Prompt (dataset): https://files.catbox.moe/ii1j1o.7z

Prompt (dataset): https://archive.org/details/prompts-dateset

Discord link for more images: https://discord.gg/HvzRZB4u

These are my best models

Abby: https://civitai.com/models/265513/abby-riding-shotgun

Elizabeth - Burial at Sea: https://civitai.com/models/257??8/elizabeth-burial-at-sea

Elisabeth: https://civitai.com/models/240263/elisabeth

Effie: https://civitai.com/models/172115/effie

Circe: https://civitai.com/models/245858/circe-generator-rex