Books like Hayate the Combat Butler, Vol. 01

Hardworking Hayate has a plan to pay the yakuza--who are now the legal owners of his vital organs--back: he'll kidnap someone and ransom them for a mountain of money. But things get tricky when his would-be kidnappee--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 hires him to be her personal servant. At least his employment future is secure, or so he thinks...