# Shimoe Koharu (Blue Archive)
下江コハル (ブルーアーカイブ) / 시모에 코하루 (블루 아카이브) / 下江小春 (碧蓝档案)

Note: this is an older LoRA that I recently retrained.  I think the quality of the captions is lacking and as such this LoRA doesn't perform quite as well as it should.  I'll re-tag the dataset when I have time.

[Download here.](chara-koharu-v3.safetensors)

## Table of Contents
- [Preview](#preview)
- [Usage](#usage)
- [Training](#training)
- [Revisions](#revisions)

## Preview
![Koharu portrait](chara-koharu-v3.png)
![Koharu preview](example-001-DefmixRed-v3.png)
![Koharu preview 2](example-002-DefmixRed-v3.png)

## Usage
Use any or all of the following tags to summon Koharu: `koharu, 1girl, halo, pink eyes, pink hair, head wings, low wings, twintails, blue archive`
- Hair and eye tags are optional but may help strenghten the effect.
- The tag `ringed eyes` was used in images where her unique eye design was very prominent.
- The vertical line should appear automatically, but may not always reach past her chest because artists are inconsistent in how they draw it.  You can try to describe it literally: `vertical black line running past navel` or whatever.  Don't try `tattoo` unless you want womb tattoos.

For her normal Trinity outfit: `school uniform, black shirt, off shoulder, hat, beret, bra strap, skirt`

It does a decent, but not perfect job with her eyes. Adding some combination of `embarrassed`, `open mouth`, `swirly eyes` with varying degrees of emphasis can draw out her characteristic horny retard look.

I tried to add the slit pupils expression and the model sorta gets it, but not very well.  You can prompt it with `slit pupils` and `flustered` but it generally creates abominations.

Some of her swimsuits are in the training data, too.

## Training
*Exact parameters are provided in the accompanying JSON files.*
- Trained on a set of 183 images; 170 normal, 13 slit pupils/flustered.
  - 4 repeats for normal
  - 5 repeats for flustered expression outfit
  - 3 batch size, 7 epochs
  - `(170*4 + 13*5) / 3 * 7` = 1739 steps
- 0.078 loss
- 832x832 training resolution
- `constant_with_warmup` scheduler
- Initially tagged using scraped Danbooru tags, then heavily edited.
  - Removed many shit/inaccurate tags
  - Made sure important traits were present and consitently described, and traits like `halo` were consistent with actual visibility
  - Pruned lots of redundant tags and simplified outfits.  There is no `black serafuku, long sleeves`, only Koharu's `school uniform`.
  - Added camera angles and image composition hints
  - Added facial expressions (particularly `embarrassed`) and unusual pupils when present
- Used network_dimension 128 (same as usual) / network alpha 128 (default)
- Trained without VAE.
- [Training dataset available here.](https://mega.nz/folder/Wi4jRZbJ#OHhH-qsltCEbks3GF2gqmg)

## Revisions
- v3 (2023-02-11)
  - Re-trained with more recent parameters. No changes to dataset. 
  - Still overfit to her standard outfit.  Needs re-tagging.
- v2 (2023-01-15)
  - Initial release.
  - [Old version can be downloaded here.](https://mega.nz/folder/Wi4jRZbJ#OHhH-qsltCEbks3GF2gqmg)