Yin Yang Shi: Ping An Wu Yu
Japanese title: 阴阳师：平安物语
Alternative titles: Onmyouji: Heian Monogatari
Type: ONA
Source: Game
Episodes: 12
Status: Finished Airing
Aired: Apr 21, 2018 to Jul 8, 2018
Duration: 5 min per ep
Rating: PG-13 - Teens 13 or older
Studios: Blade, Thundray
Genres: Comedy, Supernatural
Themes: Historical, Mythology

The courtyard is awash with cherry blossom petals, appearing especially beautiful in the moonlight. Kagura, waking up, sits in the hallway facing the courtyard, "The courtyard at night, seems like something can happen anytime......"
Suddenly a butterfly glides past, its scales glittering.
Kochou no Sei: That's right. Nighttime is indeed suitable for telling stories.
Kagura grows sleepy under the influence of dust.
Kochou no Sei: After Kagura-sama falls asleep - that will be the beginning of the story in the dream!

(Source: Onmyoji Wiki)