Info on Yako~
As stated before, yako is a sweetie. She wants to help other people, and she's very empathetic and smiles a lot.
HOWEVER. Yako is, in truth, a little depressed, and on top of her already insane appetite, she's developed an eating disorder. Yako has linked food with her emotions; she feels the need to eat when she's happy, and sad, and many other emotions. So, while Midvalley will not have her physical need of food, he will have an overwhelming mental urge to eat as much as he can, and then more.
He won't remember any of the reasons for the depression, but will make sure he's smiling; he won't want to worry anyone.