I get why people confused, the story just abruptly jump from present to past, back and forth, so you need to re-read it again to tell what is what, not to mention, the character is kinda look alike, it easy to tell them apart if the hair color is different, but if it the same shade, you need to pay attention to the hairstyle. With that said, I don't think the stalker is Taesung from Pureness. At first I thought he is Taesung when he took a photo of Sihyun hitting Eun Sung because he is concerned bout Eun Sung, but at the last panel, they kinda have different atmosphere, and the stalker seem kinda obsessed with Sihyun.
I get why people confused, the story just abruptly jump from present to past, back and forth, so you need to re-read it again to tell what is what, not to mention, the character is kinda look alike, it easy to tell them apart if the hair color is different, but if it the same shade, you need to pay attention to the hairstyle. With that said, I don't think the stalker is Taesung from Pureness. At first I thought he is Taesung when he took a photo of Sihyun hitting Eun Sung because he is concerned bout Eun Sung, but at the last panel, they kinda have different atmosphere, and the stalker seem kinda obsessed with Sihyun.