@flxsemi In part because this was semi-autobiographical. Toko Kotoha professed she lived like this- as a cripplingly depressed shut-in that refused to go to school for most of her middle school years. During that time she read a lot of Kouji Kumeta's black comedies like Katte ni Kaizo and Sayonara Zetsubou-sensei, which serve as the inspiration for the rest of this series and its dark humored moments. This wasn't the only series the she wrote about the subject either, there's also "The Day I Stopped Going to School", which was a much direct take on this period.
Well, the circumstances are soul-crushingly depressing. But this manga is a testament to the author having lived; so let's not let it die in obscurity.