@korppi That entire plot thread seemed to have vanished, much to Ashiya's relief. Still, I can see two three obstacles in the way.Ashiya pretty much went back to Ente Isla for work. While Rika probably wouldn't have major issues following him, I got the sense that her family kind of expected her to stick around and help with the family business. While not expressly stated, I think we can assume that the "issue" that effected Maou would occur to any demon that developed romantic feelings for a human. Unlike Maou, using the same treatment on Ashiya would not be well received. I really don't think Ashiya was into Rika as she was into him.
ETA:Chiho was always best girl and the frontrunner to land Maou. How can anyone complain? Chiho's end of story revelation kind of made it obvious that Maou would end up with both Emi and Sukano. Again, how can anyone complain? Both Emi and Sukano would have killed Maou for real if he broke Chiho's heart, especially after Emi removed the biggest reason why they couldn't be together.