^I don't think Maomao is Ace, more that she's never really thought about love in regards to herself and has been focused on learning
Also BakemonoJoker I think it's the type of story where romantic interest builds over time. Very slow burn on the romance as the story focuses more on character drama, crimes, and so fourth. Where she's put off by him at first but that changes over time, which I think is somewhat common in stories with eventual romantic progression regardless of gender and sexuality.