Gomi Shuushuuin: Saienji no Ryuugi
悪党収集員 : 西園寺の流儀 · ごみ しゅうしゅういん : さいおんじ の りゅうぎ
est. Rough estimate based on volume count, reprints and magazine — not an official figure
External databases: AniList
How to compare editions, collected volumes and ISBNs / Sources, updates and corrections