Lanbao is mentally 40 years old, so he might seemingly prefer more composed girls. But you never know. Some calm men actually like very energetic women. But you can be energetic in different ways as well. I reckon Lanbao doesn't like that kind of obsessive and persistent girl. Mianhua hasn't actually shown any straightforward romantic interest in Lanbao, so despite being quite energetic as well, she might be far more what Lanbao is looking for in a woman. Plus she can actually reflect on things and does possess a bit of life experience. We haven't had that many scenes with her, but the blond girl, whatever was her name, has been like a brainless bimbo so far, full of nothing but her own desires and selfishness.