The message of this manga can be condensed into the phrase "bears are scary, but humans moreso." Sure, bears will kill and maim, but humans systematically torture animals. Of course, this message is presented with the humor of seeing a tubular bear popping out of a bush like a jack-in-the-box, sharing unsolicited tidbits of knowledge, and then immediately retreating.
This is a short (4-pages!) and funny oneshot about a trio of bunnies who meet a bear in the forest, and learn that there are scary things in this world. It's an absurd form of humor I very much liked, my only regret is that it isn't longer...