Kemurikusa (2018)
Genres: Fantasy, Sci-Fi
Type: ONA, Episodes: 7
Aired: Aug 31, 2018 to Apr 6, 2019
Source: Original
Rating: G - All Ages
Synopsis:
Prequel vignettes to the Kemurikusa TV series released on Tatsuki's official Twitter. They have an irregular episode count as follows: ep 0 (in actuality, it is unnumbered), 0.5, 0.6, 0.7, 0.8, 0.9. 

After the Kumurikusa TV series finished airing, Tatsuki released another vignette the following week numbered ep 12.1 both on his Twitter account and official YouTube channel for a grand total of 7 web shorts tied directly to the TV series.