Kemurikusa is a set of seven short ONA vignettes that serve as a prequel to the Kemurikusa TV series, mixing fantasy and science fiction. Tatsuki shared them on his official Twitter, and their numbering is unusual: an unnumbered episode 0 followed by 0.5 through 0.9. A week after the TV series wrapped, one more vignette, labeled 12.1, appeared on his Twitter account and his official YouTube channel.