Here's a LoRA specifically for Iroha in her underwear
The relevant clothing tags are shrug \(clothing\), sarashi, bike shorts or shorts, and fingerless gloves. Of course, since this lora focuses on a specific set of clothing, these aren't REALLY needed. The covered navel comes up pretty much automatically, you might find that there are two bellybuttons, in which case you should put navel in negatives.
I will repopulate Japan
https://mega.nz/folder/dfBQDDBJ#3RLMrU3gZmO6uj167o-YZg/file/oaYB0ZaQ 