The Ending of 'Mahoromatic'

GRUMBLE GRUMBLE GRUMBLE

Something that I've always wondered about that horrible last episode, (with no mention of the fate of the other girls, Suguru physically and mentally scared for life, and only the Class teacher coming through unscathed... Was this a ending created by GAINAX Studios, or was it actually based on the Manga (which predated the anime series)???

I don't know who made the ending but now that I remember it.
The teacher didn't age one bit. Even at the ending she was hitting on one of her students and could recognize Suguru after so many years.