This model is trained on illustrations by Shigeru Sudō (†1946). Sudō's style is Lyrical Painting (叙情画 jojōga), with works featuring in Japanese girls' magazines spanning from around 1926 to 1940.

This first version was trained using Flux Gym with downscaled 512p images, and while it captures the style well, I would like to try again with a higher resolution. The first version also retains white borders from the training images, which you may or may not like. I will probably remove the white borders from later versions. Lastly, since the training images all have people showing their faces, it maybe take some finesse to get a character to face away from the viewer.

On FLUX Dev, increasing the LoRA strength to 1.2 or 1.3 may help. On FLUX Schnell, it may help to kick the LoRA strength up as high as 1.5 to really get the rough coloring and prevent FLUX Schnell from increasing the contrast too much.

https://ja.wikipedia.org/wiki/%E9%A0%88%E8%97%A4%E3%81%97%E3%81%92%E3%82%8B

Translated excerpt from Japanese Wikipedia about Lyrical Painting:

The term jojōga (叙情画) was coined by Fukiya Kōji (蕗谷虹児). For Fukiya, jojōga referred to paintings that express hidden sorrow outwardly. It often refers to illustrations of beautiful young girls, infused with the spirit of Taishō Roman (大正ロマン, Taishō Romanticism), created by artists such as Takehisa Yumeji (竹久夢二), Takabatake Kashō (高畠華宵), Fukiya Kōji (蕗谷虹児), Katō Masao (加藤まさを), Sudō Shigeru (須藤しげる), Matsumoto Katsuji (松本かつぢ), Tanaka Ryō (田中良), and Nakahara Jun'ichi (中原淳一), who illustrated for girls' magazines like Shōjo Gahō (『少女画報』), Reijokai (『令女界』), and Shōjo Club (『少女倶楽部』).

https://ja.wikipedia.org/wiki/%E5%8F%99%E6%83%85#%E5%8F%99%E6%83%85%E7%94%BB