I posted on a different chapter that I think Yui is the best girl (path of least resistance, and harder to keep the story line entertaining) but it seems the author has a thing for Yuki (Tsudere drama queen is a much easier to write in an entertaining way). Of course I would love to see the challenge for the author to write in Iroha, Haruno, or Hiratsuka as possibilities because when these 3 people pop up we know something is going down.