It's Mokyeon's delusion, that Nanjo like him, that is why the title is "The Boundary of Delusion". It depicts the thin line between reality and delusion. Mokyeon definitely is on delusion that Nanjo like him or that Nanjo cares about him when clearly not. I just hope he will face reality and instead of finding love from others he should start it with himself. But Mokyeon is really too pitiful...

I keep seeing ppl say that nanjo likes mokyeon but does he? Also ik that mokyeon is desperate, but i wish the author hadn't given him the crazy eyes. I'd rather have him know he's desperate and have a grasp on reality than use manipulative and stalkery behavior like this :/