Wu Nao Monu
English title: Agate
Japanese title: 无脑魔女
Type: ONA
Episodes: 15
Source: Web manga
Genres: Drama, Fantasy
Studios: CUKA
Producers: bilibili
Duration: 8 min per ep
Rating: PG-13 - Teens 13 or older

Agate is a demon girl cursed with an eternal life. To forget the past, she throws half of her head into a deep valley and runs away. Unexpectedly, the tears flood the valley floor and form into a lake, triggering a flood in hell. Aloys, the Prince of Ghost comes to the Human World to find out the truth and finally finds the demon girl, starting a story of life and love.

(Source: Bilibili YouTube)