Oh God. They introduced TWO GUYS with names AND faces. I'm officially terrified that this is going to have a het ending. I ought to abandon ship now. The fact that I've never even read a korean series with a lesbian in it doesn't help my fears and concerns AT ALL.
Stay aboard!
I'm optimistic that this will have a yuri end. If not, it will have sweet yuri moments throughout the story at least.
Why worry about the unknown ending if it can make you a little bit happy now?