Ouran Koukou Host Club, Ghost Hunt Recommendations
It's another great comedy/romance shojo series, although it's definitely got less of a horror/mystery flavor.
Both main characters are forced to join the club/company after breaking something worth a lot of money.
The beginning to both animes are alike, in both a girl breaks something expensive and is forced to work for the people whose item it was to pay off that debt.
The girl is forced to join the club because she broke an important item of the club. Instead of romance, it has a horror and comedic vibe. Not a harem or reverse harem though. Just mysteries and cases to solve.