It's Hyorish
Only the first track sounds good to me, imo. The rest are alright. I guess I'm just not into K-pop that much anymore. :/ I still think Hyori's voice don't match with her looks. Her voice is a bit low, kinda husky (but not like a man's) which I find unique. But looking at her face makes me think she has a girly voice. XDDD;