Beelzebub: Satura (Sachura) and Izabella.

 One of Lord En's nurses Satura tends to be the one to bring him his drinks.  Of En's three maids Satura is the most cheerful and will be the first to suggest doing something fun.  But, do not be fooled she is dangerous; especially when someone threatens En.  

Izabella is the leader of the three nurses and unlike Satura she is serious and much more stoic (Except when En starts to cry).  She has a book of incantations she uses to help take care of En's needs and whims.  She also only wants the highest quality foods for her master.