I was finally able to get a more better NPR/toon shading.
The model was sculpted in blender using dynamic topology and for the toon shading, I learned from AtsushiTamaki techniques. Link is here. make sure to use chrome and translate in english: https://tama-chan.jp/
For the character, her name is Reina. The model is only a head sculpt, so I haven’t retopo Reina yet. The hair bangs are made from nurbs curves.