Shan Hai Qi Tan

According to legend, the world used to be a very different place. Exotic beasts, spirits, and youkai lived with humans in peace. But as time passed and events occurred, the spirits and demons eventually hid themselves away.

(Source: Tencent, translated)

Notes:
Season 1: 15 chapters and 2 extras
Season 2: 31 chapters and 6 extras