SHOUWA GENROKU RAKUGO SHINJUU: YOTAROU HOUROU-HEN

Bundled with the special editions of the manga's 7th and 8th volumes. The story revolves around a mature prisoner who was released on good behavior during Japan's Showa Genroku era (1960s to early 1970s). He is called Yotarou by others, a term that means an "anti-hero" or a "dim-witted man." When he returns to society, he starts a new life in rakugo (comic storytelling). Touched by Yakumo's role as the "grim reaper," he asks the master to take him in as an apprentice. (Source: Anime News Network) — Description from AniList community (anilist.co).