Well, I think the novel that's more similar to 'The Ambiguity Expert' is 'The Amazing Adventures of the Adventurer of Love'. It's also a novel about urban life. It tells the story of a love expert that girls can't resist. He seems to be able to solve all the problems, but he can't extricate himself from his own feelings. Moreover, the plot of this novel is very interesting. I recommend it to you. I hope you like my recommendation.π