"Tsuki ni Naku" will take the story content from volume 11 of the manga, which features a visit to an onsen by the members of the Hiizumi Life Councelling Office, while the town's police force have to deal with a new youkai-hunter threat.
This OVA is bundled with the limited edition of the manga (14th, 15th, and 16th).
— Description from AniList community (anilist.co).
