Dou ka Ore wo Houtte Oitekure - Vol. 3 Ch. 16 - I Didn't Want to Go Through the Experience of Saving a Beautiful Girl from Bad Guys, Alright?

[Skyu]

I'd actually ask you to pass the dutchie down the left hand side, because you're the one smoking something. The MC has the ability to interact and react normally. He's chosen NOT TO, which simply makes him worse than he really is. He's not mentally incapable unlike a higher rating which would require intervention and medical guidance. It's his cowardice, which is a moral, not mental characteristic, that's failing. Stop conflating the two.

To add to your point, Nanamura is able to rationalize the reasoning why he doesn't interact with others and those reasons are pretty sound. That isn't mental illness. If I were to give a proper comparison the person who can't talk to others wouldn't be able to figure out where they are going wrong before delving into self-hatred. Mind you the ones with mental illness would continually fail in their approach to others and fall into the same traps every time until someone was able to approach them and tell them what it is they're doing wrong.

 

[Nobi]

Did he really have to save her heroine? I swear Japan has a secret AI project and the visual novel market is a test run.