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. Now the butler of a wealthy young lady, Hayate can finally pay back his debts, and it'll only take him 40 years to do it.

The boardinghouse is about to get even more crowded! Ayumu is determined to spend the summer under the same roof as Hayate, but how can a perfectly ordinary teenage girl afford a room of her own? Meanwhile, the perfectly extraordinary Ruka gives up pop stardom to pursue her artistic dreams and move in with the gang. But what's with the seriously bad mojo emanating from the attic?