I was really doubting the author for a minute there, not sure if they'd manage an ending I'd think was decent... but this made me tear up a bit and I'm happy with it. I get why people are asking why kill the grandma, but I'd argue why leave her suffering up in the air and Kim Dan being able to be sad yet accepting of her passing was definitely an aspect of his character development. Def looking forward to some side stories to see more healthy relationship building between Jaekyung and him, as well.
I'm not the type that thinks a story should have gone on longer, but with this one I would have truly loved to see more of them together after our ultimate super duper #1 alpha boy murked all the losers :')