Is mischief out of character for Eimi? I'm not familiar with her source, but the degree of adventurousness required to tag along with Doug as a laptop... Well, the two kinds of protagonist I enjoy the most are the Outsider, who is flung or dragged unwilling into the plot, and the Trickster, who is by definition mischievous. Whenever it isn't obvious that they aren't, I tend to assume any protagonist has at least a faint resemblance to one or both – and Eimi is completely willing and not at all Outsider-like, so that leaves the Trickster.
Incidentally, the term "Outsider" (which I invented on the spot trying to express myself) doesn't have anything to do with the protagonist being foreign to the main setting; that's just the most obvious cause which gives the entire concept a convenient label. What makes an Outsider is the explicit goal of a resumption of normalcy, of returning home. Doug is an Outsider, but Eimi is almost the antithesis: she jumped at the opportunity to leave home, and has no particular plans to return to Fenspace.
Incidentally, the term "Outsider" (which I invented on the spot trying to express myself) doesn't have anything to do with the protagonist being foreign to the main setting; that's just the most obvious cause which gives the entire concept a convenient label. What makes an Outsider is the explicit goal of a resumption of normalcy, of returning home. Doug is an Outsider, but Eimi is almost the antithesis: she jumped at the opportunity to leave home, and has no particular plans to return to Fenspace.