She may be cute, but she's also a bit cuckoo crazy. I don't know if she's a yandere or not, but I think she is due to her unhealthy obsession with her crush, as well as the screaming fit she throws shortly into her song and immediately entering a crazed trance. It's pretty much safe to say that her lovesickness has made her a little nuts. I'm sure that later in the game, Jamtine is going to be rejected by her crush. The immature and insensitive way she acts, never pausing to actually consider her crush's feelings, is just asking for it.