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?