1. The reason Aaron can't fall asleep without Yujin's music is because Yujin happened to be there the day Aaron was being "hunted" by the man. Yujin (maybe) happened to be singing and caught Aaron's attention that day, thus calming him down.
2. The reason why Yujin dates people who look similar to Aaron is because he doesn't remember who Aaron is, but just remembers a boy with blonde hair and green eyes. So he subconsciously seeks out people who look similar to Aaron.
In the end, they probably unknowingly saved each other from their own traumas. See y'all in 40 chapters or so.
I'm gonna make my predictions early and guess:
1. The reason Aaron can't fall asleep without Yujin's music is because Yujin happened to be there the day Aaron was being "hunted" by the man. Yujin (maybe) happened to be singing and caught Aaron's attention that day, thus calming him down.
2. The reason why Yujin dates people who look similar to Aaron is because he doesn't remember who Aaron is, but just remembers a boy with blonde hair and green eyes. So he subconsciously seeks out people who look similar to Aaron.
In the end, they probably unknowingly saved each other from their own traumas. See y'all in 40 chapters or so.