@Victormg To be fair , he sacrifice his social life to games so he probably not doing everything an adult would be doing. I would assume he have a job (even if he said he is unemployed )since he cannot finance the games and I don't think the government is that generous to subsidies his lifestyle. Japan definition of NEET also include jobs the society does not consider a job, part timers also considered NEET) .Other way is like those e-sports competitions and sponsorship. That aspect of an adult could be said that he has them albeit barely.
However, in social, relationship and especially romance side, he probably act like a teenager as evident on his laughing in public and weird behavior.
@davremedy She ain't qualified to teach that considering she overreact, let bias get way with her judgement, also lacking common sense(expensive looking clothes doesn't always mean he is a noble. ) as she was reprimanded by her superior. She is hardworking yes, but she is overzealous in performing her duties.