It's auto-translation; you need online access and to wait a bit [minutes I believe] for the translation to run.
Remember playing it some time last year, I believe; it was alright, imo.
Tips:
Monsters are useful at the beginning, then it's traps because of the numbers. -- Traps stay for turns, so they're constant for the round, while monsters get killed.
I also recommend placing max amount of monsters in rooms, 3 IIRC, instead of them being separate.
Even the lowest goblins can be useful; IIRC I was still using till near the end.
Edit: Forgot: Some of the girls have scenes where you need a certain number of a monster species/type, was tedious.
Edit: Also, you're technically not the demon lord, but fool/take advantage of the naive female DL; she's the first 'heroine'; the blonde to the left. Reason why she's at the end of the dungeon, and if she's taken out, it's game over. -- Though, I may be remembering wrong.