Her moving on is a possibility, yeah, but the story still feels a bit incomplete that way? Depends on the author's intent, really. Maybe they'll pull a cheap (but most welcome) twist on us along the lines of, "she's not a ghost, she's an astral projection of a very real and alive girl in a coma". And now that the OG girl woke up, her "spirit" merged back into her body, and now her and Kaoru will be able to meet for real.
Is it cliché? Oh hell yes.
Do I still dig it? You bet.