Note: The series' first appearance was in Web Opera Vol. 1 (it was Opera's web zoukan, released 8 vols from Apr 2018 to Aug 2019) in 2018. Never appeared again in Web Zoukan. Started on Pixiv and released short (4p) and full-color chapters in 2019. (Still can be read 3/4 of the chapters on Pixiv.) Chapters prepared by Opera Edit. Dep. (it was an official work). And finally started again as a proper series in Opera Vol. 78 as of Dec 2020 (with full-lenght chapters but no color). Resource links: https://www.mangaupdates.com/publishers.html?pubname=Opera https://comic.pixiv.net/works/6072 https://www.mangaupdates.com/publishers.html?pubname=Pixiv https://www.mangaupdates.com/publishers.html?pubname=Web+Opera