@levi da You are right that Yoomin doesn't want that type of love. But I don't think it's platonic at this point. It's not just how Iseon is describing it, it's also his facial expression and his POV from the past. You can see he's clearly sad and in the flashbacks he does see her with sparkles (LOL that's how the author made that one panel). It's how I interpret it based on how everything is drawn. He does say that when they first started the relationship he thought he couldn't give her what she wanted but then the more time he spent with her, he was so happy. I think he will be a bit late to realize it, that it's love. So I don't think it's platonic