Honestly, I understand why people don't like that Hanako is resistant to Sadako RN but I also don't think it's necessarily unfounded. Rude, yes, but neither Sadako nor Hanako have a real grasp on how to interact with others in any way besides vivacious playfulness or violence - it's a clash that can't be helped between them. They're both only surface-level interested in each other right now, so I'm excited to see where they go from here.
Also, I don't think it's strange that Hanako is so resistant to Sadako's advances. She's grown up being called a "man-girl" and consistently not seen as a woman, of course she wouldn't take well to the idea that she'd somehow be even further off the "norm" of being heterosexual. Taewol is, for her, a chance at the "feminity" of being courted and treated in a way she's never gotten to experience. (As a side note, I love that the author included a Korean character. Feels good to see one in a manga.)