The author said we'll find the answer if we read the last chapter. I am crying omg. In other words, yes he did...he was saying his name over and over (before that fricking grandma came in the room) like he needed him. I think the reason why he tried to kill Bum at the end is because he was mentally ill..And the fact that Bum had a ring for him, it means that when he left the house(when Sangwoo was scared), he bought rings. That's what he needed money for... Damn...the fact that i realized it now, hurts my soul (╥﹏╥)
It's so beatifuullll i feellll in love with all of them OMG!!!!! I love the art style and the story so much. This story was so heartwarming in the end <3