Kamen no Maid Guy (2008)

One day, high school student Naeka Fujiwara finds herself the near-future inheritor of vast wealth. But with potential wealth comes villains determined to steal it, even if it means taking Naeka's life. Therefore her mega-wealthy grandfather hires a brawny, commando-like maid to protect Naeka until her 18th birthday, which is when she can legally inherit the fortune. His name is Kogarashi, or just Maid Guy!