Hayate wants Nagi to attend school on a daily basis. One day, however, when returning from school, Nagi forgets a notebook, and as her butler, Hayate goes to the academy to get the notebook. However he arrives at night.... in an area that's supposed to be haunted!
A butler is a formal guardian,
Un mayordomo es un guardián 
formal que está ahí
O mordomo é um guardião que está sempre 
disposto a atender os desejos do seu amo.