From the flow of the story, I think Erwon/Roowon is going to be the main ML. The scary golden retriever is good too but I don't think Sera will fall for him. While, her fiancé is realizing a bit too late. Sera blushes when thinking about Erwon/Roowon too, so you know. Also Sun Kyung is really scary, don't you think? I'd rather die (well not really, maybe just not know them) than be associated with similar types of people.
Or MC can just live happily without having a relationship with any of the MLs.
From the flow of the story, I think Erwon/Roowon is going to be the main ML. The scary golden retriever is good too but I don't think Sera will fall for him. While, her fiancé is realizing a bit too late. Sera blushes when thinking about Erwon/Roowon too, so you know. Also Sun Kyung is really scary, don't you think? I'd rather die (well not really, maybe just not know them) than be associated with similar types of people.
Or MC can just live happily without having a relationship with any of the MLs.