The artwork of Vagabond is simply outstanding. Inoue Takehiko understands exactly how to fully capture the reader in his brush strokes that change to an insane degree depending on in-story situation. I have never seen anything that comes even close in leading the eye along the gorgeous artwork. Even if you don't care at all about the characters or the story, the art alone would make it worthwhile to read this work. The in-story calligraphy is nothing to sneeze at either.

The story roughly follows Yoshikawa Eiji's take on the life of Miyamoto Musashi, undoubtedly one of the the greatest swordsmen to have ever lived. The depth of his understanding of fighting and the art of the sword still eludes droves of sword students today. Starting this manga, I had read Musashi's Go Rin No Sho and the original Yoshikawa Eiji book and I think this made the experience all that more enjoyable. Some of the decisions Musashi makes along the way are much easier to understand with the background knowledge gained from Yoshikawa's book and there's various throwbacks to philosophical understandings Musashi expounds upon in the Go Rin No Sho.

Like Yoshikawa before him, Inoue takes various freedoms in timeline composition from what are the current best guesses about the life of the real, historical Musashi, but it's an action manga after all. If you see the characters as adapted from the Yoshikawa novel, then the level of adaptation is simply outstanding. They come across exactly like in the book, especially the three leads Musashi, Kojirō and Matahachi. Takuan, too, takes very well after the book character. If you haven't read the book, then the characters are still extremely well defined original characters, with clear goals, inhibited by human error and understanding, certainly utterly comprehensible in their life choices, whether your agree or not.

If any manga deserves the designation "unrivaled under the heavens", it's certainly Vagabond.