This model is trained on the new playable Sunday outfit in Honkai: Star Rail. All the training images were obtained in-game, during his arc in Golden Hour in the 2.7 story (since I didn't pull for him). Definitely not my best work, but it still should be somewhat usable.
The clothing can be a bit finicky to get all the little details correct, so try playing around with randomizing the seed.
Trigger words are "1boy, sunday", and the best strength I found is 0.9.