>>5965As far as the board title is concerned, I think it was named this way as an abbreviation, because Hikikomori has two Ks and ends in an I. HIKiKomorI. In Japanese the double K also renders as a pronunciation jump, alluding to the word being crunched down. You could also see it as the last two letters in the first five letters being flipped around for funsies.
It might have also been that someone (possibly me, don't remember) couldn't spell.