The Yangire and Yandere modes aren't unlocked unless you gotta do something to unlock them.
No, it's not a DLC type of game where you pay money to unlock features to the same version. It's two different versions: 2.0 and 2.1, with the latter costing $4. At the time of my comment, I assumed OP was referring to version 2.1 (maybe I was tired? idk), but it's obvious now s/he wasn't and just hadn't bought the 2.1 version. Instead they had probably just clicked the "Download version 2.0 " without reading that it said "version 2.0".