ハーレムヘブン : 彼女たちの秘密のレッスン
はーれむ へぶん : かのじょたち の ひみつ の れっすん
est. Rough estimate based on volume count, reprints and magazine — not an official figure
External databases: MADB
How to compare editions, collected volumes and ISBNs / Sources, updates and corrections