Dungeon no Maou wa Saijaku!?
ダンジョンの魔王は最弱っ!? · だんじょん の まおう わ さいじゃくっ
est. Rough estimate based on volume count, reprints and magazine — not an official figure
Overview
God left a dungeon in the hands of a boy known as the Demon Lord. After receiving multiple blessings from God, let’s start my life as a Demon Lord! …Or that’s how it was supposed to be, but God messed up and created the worlds' weakest Demon Lord ever. To continue living, I have to continue making dungeons. This story is about an idiotic protagonist, a lonely demons' child, an Undine who lives in a bathtub, and a princess who fell in love with the Demon Lord, even though she was human. A story that all unfolded during a bath.
Source: AniList
External databases: MADB · AniList
How to compare editions, collected volumes and ISBNs / Sources, updates and corrections