Unfortunately for Kai, she has a bipolar disorder. She tends to cry when she is presurred or when she forgets to study for a class quiz. She also tends to be obsessive and manipulative towards other people. When she is mad or jealous, she tends to be very violent.
Around other people, Kai acts sweet and cute. She socializes and proceeds to tell almost nothing about herself, she is not willing to open up to other people. Kai is also a crybaby around other people. She's not doing it for sympathy, she's doing it because she can't help but cry about the fact that she's supposedly "stupid", "clumsy" and "forgetful".
She seems to have two different personalities, A sweet and cutesy personality, and a anger-issued and violent personality.