Master is the owner of Pom and Shibe.
What we knowEdit
Not much is known about Master aside from the fact she is the owner of Pom and Shibe. Unlike her dogs, she survived the fire. She most likely loved her dogs very much as Pom (and possibly Shibe) has a room and even computer of their own. Her love for her dogs is also shown if you go to the observatory and look through it as Shibe says he sees her sitting in front of two rectangular rocks, assumed to be Pom and Shibe's graves, and crying.
She has no actual effect on the story of the game. She is mentioned by name by Shibe and Pom basically.
Master is probably Min-seo or Diya from butterfly soup, as confirmed per Brianna Lei's (creator) tumblr faq page on butterfly soup.