I was wondering what is the source of these short comics. Googled, and there's someone who already wrote a blog post about it: http://experimentsinmanga.mangabookshelf.com/2014/08/random-musings-spotlight-on-masaichi-mukaide/
So the artist is a law school graduate who apparently never a made a living as a mangaka in Japan, but somehow was able to publish this work, a collaboration with a pioneering female comic artist, without ever meeting his collaborators, and then disappeared from history. And yet he could claim to be among the first mangaka published in the U.S.! Very fascinating.
In an alternate universe where those damned bears are correctly named Berenstein, this oneshot isn't a forgotten standalone, but the first chapter of a work introducing samurai-themed manga to the West, like an expat Lone Wolf and Cub. Oh, to wonder.