Crimson Empire: Circumstances to Serve a Noble

Sheila is a housemaid and exclusively serves Edvard, a prince. She also works as his security guard because of her past assassin training. She is all-purpose at work, but awkward when she is off. Although Sheila is competent at battles and operations, but she isn't good at love and establishing friendships. She, however, needs to use the various people around her to have Edvard take over the throne...