Hayate no Gotoku!

Synopsis

From Viz: Hardworking Hayate has a plan to pay back the yakuza, who are now the legal owners of his body parts. He’ll kidnap someone and ransom them for a mountain of money! But things get tricky when his would-be kidnapped, who as luck would have it is the daughter of a mind-bogglingly wealthy family, mistakes Hayate’s actions for a confession of love and subsequently hires him to be her personal servant. At least his employment future is secure, or so he thinks.

Synopsis & details from MangaUpdates