In volume 6, Scott takes Wallace's advice (forcefully) and goes on a wilderness sabbatical up north while also visiting Kim.
He stays with Kim and while going out in the woods, Scott kisses Kim, admitting that everything with Ramona had been complicated and that Kim was the one constant in his life.
2 when the panel shows Scott and Kim in a car and she tells him, "Listen to the song. However, the relationship ended when Scott's family moved to Toronto.
This comes after Kim rants on about men, then Knives says "I've kissed the lips that kissed you," referring to Scott (After Scott seeing them he said to himself "let us never speak of this again"). Finally, towards the end of the same book, Scott secretly refers towards the incident by suggesting that Kim keep the poster of two girls kissing as he moves in with Ramona.
Whether or not this was some kind of consolation for Kim is anyone's speculation. Kim is played by Alison Pill whose previous works include roles in Milk, Confessions of a Teenage Drama Queen, and Dan in Real Life.
As Scott leaves to fight Gideon back in Toronto, Kim gives him one last kiss for luck, but states "it'll never happen again." Kim appears during the final battle between Scott and Gideon, somehow aware of the battle even though she is still in Northern Ontario.
When Kim comes back to Toronto, she and Scott form a new band, "Shatter Band".
In the modern story, Kim expresses annoyance at Scott's many faults and generally tries to forget that she dated him, but she still feels some repressed affection for him and puts up with a lot of his crap.
She helps Scott score a job, is the drummer of their current band "Sex Bob-omb" and is recognized as important by Ken and Kyle Katayanagi, who kidnap her in order to lure Scott.
Kim pleads with Scott that he can't keep forgetting his mistakes without them following him behind, telling him to live with it and to hold on, so he won't repeat them again.
Scott suddenly remembers everything, including Ramona and accepts Negascott as a part of him.
Ramona decides to get some alone time from Scott while he deals with the twin's robots and Kim joins her.