After the death of her mother, "Ruby" became a maid for the noble Bell household, thanks to an old friend of her mother, “Mrs. Watson”. There she meets “Grace”, a noble lady born into a completely different class. Although Ruby thought her to be another spoiled aristocrat, soon Grace became the only one in the Bell household that took good care of Ruby, which led Ruby to blossom particular feelings towards her. How will this develop a curious relationship between these two, and what kind of secrets do they keep from each other?