>>25104069
I don't think something like that would sell well, so consequently it doesn't really exist, or at least it's extremely difficult to find such media.

The manga Ressentiment is the closest thing I can think of.

welcome to the NHK

>not an original comment

>>25104069
tatami galaxy is the closest i can think of

>>25104222
Maybe for the first episode, but even though there are still plenty of relatable moments after that, it loses the feeling of total isolation.

>>25104235
Doesn't really give the sense of intense self-loathing or loneliness.

The book "Notes From Underground" is really the only satisfying piece of media I've experienced with this concept.

>>25104222
he has 3 friends he hangs out with

>>25104360
having friends doesn't make you not alone

also are you seriously asking for a show where a guy just sits in his room for 13 episodes

>>25104069
Natsume Yuujinchou is a lot about loneliness even if the MC slowly gains friends throughout the series

Serial Experiments Lain is essentially about the isolation of modern technological life

Casshern Sins is a bit angsty but existential loneliness is a central theme

Texhnolyze is not totally about loneliness although the MC becomes progressively more isolated until the end

I highly recommend you read Legend of the Strongest Man Kurosawa and Goodnight Punpun