Would it be too much to ask from a TWENTY FIVE years old guy to stop acting like a typical Romcom teenager? Has the author already forgotten he is a time leaper?
Brother, there are 50 year olds that are socially awkward, much more so than the MC lmao. Do you think people just magically become mature at 18? He was a gloomy guy and antisocial from the beginning, and it only got worse after her death in the old timeline.
What does a 25 year old with a personality like that even act like that he isn't doing? I'd say mature teenagers are more mature than a lot of adults.
MC is pretty mature whether for a teenager or an adult, sure he's not as mature as a 1980s parent who had to raise 3 kids by himself, but that's not the life he lived so what do you expect? It kinda sounds like from high school to 25 he just kept to himself and worked at a black company for a few years before he died from karoshi. None of that would make anyone particularly mentally mature. It's the same reason Rudeus, despite being 34? at the start of MT, still acts like a guy in his late teens, because he was a shut in hikikomori from 14-34. How do you expect someone to have the maturity of a grown adult when they stay in their room for 20 years and never leave it? and their only interaction with people is flaming them on 2ch? That's not how you become a mature person lol. People mature in response to things that need them to become mature.