Hayate the Combat Butler Vol 50

A hilarious tale of butlers, love and battles! 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. Everyone is searching for the key to the Sanzenin fortune, and only Hayate knows where it is. Unfortunately, it's in a cursed castle that can only be accessed through the power of ultimate suffering. Blame Nagi's mom and her questionable idea of fun. For Nagi's sake, will Hayate break a heart? Will Maria quit her job? And will anyone tell Nagi that her manga about marrying Hayate is completely disconnected from reality?

Source: Anime News Network Encyclopedia