Shinwoo bracelet.

 Kuebiko:

I was thinking if the bracelet that TK is wearing is the same bracelet that he gave with Daon, it's like a couple-bracelets, though we didn't see that TK bought two of the same thing, and he only wears that bracelet after he confessed his feelings with Daon.

In regards to this question, I was wondering as well if it's TK, or maybe it's just a backstory of SW to be able to know that he likes guys, that he's brave enough to open his sexuality during middle school in spite of the stigma.

I also thought that the bracelet was a couple bracelet. Going back to episode 8 I saw that it had two strings but after watching carefully from ep 1 I saw that Tae had been wearing the bracelet from the start. He likely bought the same type for Daon because he liked him. Anyway there's no doubt that these two bracelet look exactly alike.

 Naruxsasumi:

But Tae doesn't even remember Shinwoo or notice him at all. Why would he wear a bracelet a stranger gave him all the time. Makes no sense.

IF Tae was the one Shinwoo liked in MS, maybe he didn't directly give the bracelet to Tae? Like maybe he left it on his desk or in his locker with a note but didn't reveal who he was? Maybe the note said something sweet or inspiring so Tae kept the bracelet even though he didn't know who it was from? Shinwoo may have told his friends he bought a bracelet and was going to/did give it to a boy but they didn't know who. They started bullying Shinwoo so he never revealed who he was to Tae or who the boy was to the friends?

I do think it's odd that after bumping into Shinwoo he immediately wants to make friends. Maybe on some level he did remember Shinwoo (subconsciously) so after bumping into him that day it made Tae have that desire.

 Azalea1012:

IF Tae was the one Shinwoo liked in MS, maybe he didn't directly give the bracelet to Tae? Like maybe he left it on his desk or in his locker with a note but didn't reveal who he was? Maybe the note said something sweet or inspiring so Tae kept the bracelet even though he didn't know who it was from? Shinwoo may have told his friends he bought a bracelet and was going to/did give it to a boy but they didn't know who. They started bullying Shinwoo so he never revealed who he was to Tae or who the boy was to the friends?

I do think it's odd that after bumping into Shinwoo he immediately wants to make friends. Maybe on some level he did remember Shinwoo (subconsciously) so after bumping into him that day it made Tae have that desire. 

This is impossible, why? Because Tae and Shinwoo met in highschool, not middle school. Someone explained it in details in the comment section which makes more sense to me than Tae finding a bracelet someone left with something sweet written on it and wearing said bracelet everyday without bothering to find out who it was from.

Also, you make it seem as if Tae only wanted to make friends after meeting bumping into Shinwoo. That's unlikely because they've bumped into each other many times and Tae didn't even remember or notice Shinwoo. Tae had also been thinking of changing way before he met Shinwoo and official noticed him and his first thought was that he wouldn't someone like him for a friend.

Shinwoo is already winning, why is it so important that we create stories for him that connects him to Tae.

I feel that the theory could be true. There is  maybe a story behind Taekyung's bracelet if not why would it be part of the animation at the end.  The keychain has it's significance so does the bracelet. Why would they hide the boy of Shinwoo's past if it was highlighted about three times in the drama. They could have shown us who the boy was if they were not hiding him. It would be a shame if they were emphsizing on the bracelet for nothing