oops sorry I havent checked neocities in a while D:!!!!! but what I know is yotsuba& is still being updated so newer volumes might be easier to come by. it all depends on location but for me amazon and a local bookstore sells the volumes! you can check proxy sites (like fromjapan or zenmarket) but I cannot guarantee the prices wont be marked up.
hopefully winter break coming up will allow me this time. i have some inspiration as of what i'd like to do!!!! and hopefully get a start on other pages like my about me