Guys there's been a theory for Yuu's behavior that it's because he either has cognitive dissonance or he's playing dumb. Hopefully it's the latter but there's also a possibility that how he acts is a coping mechanism. Remember that time where Yuu easily tricked Shinoa's demon/angel? (the name was Shi idk) if Yuu can trick them then there's no way he couldn't trick others. In the former, it makes more sense but honestly I hope it's the latter.
For more details of the theory:
https://twitter.com/doglovermax/status/1356342046617972737?s=19
Why isn't anyone gonna talk about how cute the boku/ore part was
Page 5: the difference between the TS/N and QC/N lmao
I just realized this manga doesn't have romance is in it's genre. I also don't know how I found this manga but I'm glad I did find it...-