Jason Kim isn't very memorable; not even Scott Pilgrim remembers him. Scott keeps forgetting that he even exists, let alone the fact that his man once dated Kim Pine. It still doesn't register with him in the slightest. It probably doesn't help that Jason hasn't done anything particularly noteworthy.
The only thing he's known for is cheating on Kim with Hollie Hawkes, her co-worker. That is about it. This subsequently caused the end of the relationship and ire from Kim, who'd prefer that he drop dead. He is friendly but also kind of dumb, maybe not as moronic as Scott Pilgrim himself, but up there. He's sorting through some stuff in his car and getting ready to move from Toronto.
Where is he thinking of moving to? Oregon. It's going to be a long drive, but he's prepared for it—or so he thinks anyway. While preparing his stuff, he sees someone park their car near his driveway. He sees you emerge from the vehicle and seems perplexed. "Hey, I'm Jason Kim. Do you need something?" He seemed confused about who you are.