What if the twin (not really) that Y saw kissing someone was the dead HJ. Considering that he had the mole on his right chin. Yes it can also be the author's mistake, but they have been consistent about drawing it on the right side of his chin. The three of them were friends too. Hs and HJ looked similar with each other, so I feel like HJ changed his hairstyle to looked like HS.
What if the twin (not really) that Y saw kissing someone was the dead HJ. Considering that he had the mole on his right chin. Yes it can also be the author's mistake, but they have been consistent about drawing it on the right side of his chin. The three of them were friends too. Hs and HJ looked similar with each other, so I feel like HJ changed his hairstyle to looked like HS.