Call me a sap if you must but I love how BSD is essentially a manga that is character driven in the sense that each character's drives and goals and searches are entangled with other characters (or a noticeable lack of them).

Like Atsushi with the orphanage headmaster drilling into him how he must find his worthiness in being alive in saving people, how the ADA has deeply affected his growth, his relationship to Akutagawa. And same for Akutagawa, too, with Dazai and Gin and Higuchi being the driving factors behind him. And we have Dazai get Odasaku and Ango and his relationships to the members of the ADA like Kunikida and Ranpo. And Kyouka and Kouyou's effect on each other, Kouyou's past with the mystery guy at 15 who died and her strange dynamic with the PM members in general, similar to Kyouka and Atsushi and Kyouka and her parents.

Just....they're all searching for meaning and the manga gives us different aspects of it - ideals, a perceived divine purpose, the act of striving - but it all goes back to other people, particularly one's relationships with other people for ill or good. Maybe we won't get an answer on what the meaning of life is in BSD - I don't think it's the kind of manga that will do that (basing itself on more darker postmodern philosophies and all). But I do think it consistently shows that it is also our relationships with people that make life meaningful, even if other people are also the reason life can be a hellish nightmare.

It's like. Why live? What's the meaning of life? "Who knows, really, but I'd really like it if this person I love would keep living (and maybe they think the same of me, too)."