Board Thread:General Discussion/@comment-98.206.30.85-20190604230642/@comment-29602226-20190704164554

The monsters were transformed into mamono at least a thousand years ago, so not many of the current mamono used to be monsters of old, but rather they were born as monstergirls...

At least one mamono, the Baphomet Ropurotto feels so bad about her past that she has chosen to erase all her memories.

Most Genies and Pharaohs were born during the previous era (and in fact, they are older than the first Demon Lord!), but they were allied to humans, so they don't feel bad about it...