Since the tender age of nine, Hayate Ayasaki has busted his behind at various part-time jobs to support his degenerate gambler parents. And how do they repay their son's selfless generosity? By selling his organs to the yakuza to cover their debts! But fate throws Hayate a bone...sort of.
Final exams are close at hand and Hayate can no longer afford to ignore his studies, but if he's hitting the books, who will keep the Sanzenin mansion spick and span? Anticipating just such an occasion, head butler Klaus arranges for Mecha Butler No. 13 to take Hayate's place. Fully automated and machine-engineered to domestic perfection, this new cybernetic manservant boasts a wide variety of dazzling features and capabilities, from performing soothing backrubs to giving Nagi candid advice on her latest manga. Is Hayate truly this easy to replace?