
Exactly. I think he's special.
they usually forget about her after she rejects them because they betray her in some way. I also think part of it is that on some level they want to forget her since they probably now know that she's not human. But what if this guy didn't betray her, just seemed to? And when She left, maybe he forgot for a while or something, but remembered her after a bit and started pursuing her following small clues. Fighting against this memory block and this magic that has him always half a step behind her. My evidence to support my theory: 1. He kinda has that haunted look that the guy from the first story had after he betray yuki. 2. how she never seems to see stalker guy despite her being super human. (perhaps they ~just~ miss each other) 3. his notebook never seems to mention that he actually finds her. or at least actually encounters her.
i think the stalker guy was one of her past lovers who can't forget about her.
But neither can he seem to quite catch up to her.