Gungrave: The Complete Set covers the adult years of Brandon Heat and Harry McDowel and their climb up (and down) the ranks of the Millennion Mafia group.

Highlights

Brandon Heat doesn't say much, but he's a loyal and physically powerful guy who only wishes to protect the one's closes to him.  After three of his best friends and the Uncle of Brandon's love, Maria,  are murdered by a rogue Mafia member, Brandon and Harry McDowel have nothing left.  They've lost their gang member, their family, and now Maria has been taken by the Mafia group Millennion.  It turns out that Millennion just wants to take care of Maria, because her uncle was a good friend to the boss, Big Daddy.  Brandon knows she'll be okay, but he still misses her.  

Not long after the deaths of their friends, Brandon and Harry are offered positions in Millennion, which they take willingly.  Harry starts working for one of Big Daddy's Family members with business, and Brandon works with Bear Walken to become a Sweeper for Millennion.  Eventually, Harry becomes one of the most influential members, and Brandon is at his side being the best Sweeper there ever was.  Brandon has also become good friends with Big Daddy, and has met back up with Maria.

When the time comes for Big Daddy to retire, everyone thinks he'll choose Harry as the new boss of Millennion, but, at the meeting, Big Daddy did not choose Harry.  Well, Harry doesn't express that he is upset, instead, he is the first to applaud the new boss.  

Three months pass, and Harry has finally become the boss of Millennion, because the one Big Daddy picked ended up in the hospital.  Brandon is still very close to Harry, vowing to protect him and uphold the Iron promise.  Then, Harry grew suspicious of Brandon after he reveals a secret that would go against the Iron promise.   Brandon realizes that he now has to kill Harry, but, he is unable to.  Harry then pulls out his gun and shoots Brandon without understanding what Brandon really wanted.

Harry continues to rule over Millennion, and with an iron fist now that Big Daddy has been disposed of.  The whole time Harry was funding secret research on the process of necrolyzation, bring the dead back to life with enhanced power (basically turning humans into monsters).  When the time comes to finally test his new found power, a technical error happens and the research facility is utterly destroyed.  The monsters are accidentally awakened, but the controlling program has not been imputed in them.  They attack everything, but then, a mysterious man appears and shoots the monsters down, then disappears.

It turns out that Brandon Heat was not quite dead yet, he has come back as Beyond the Grave, and is determined to achieve revenge against those who ruined his life.

Extras

The extras include Conceptual Art, Textless Opening and Ending, and Promo Videos.  Expect for the Textless Opening and Ending, the extras were pretty neat.  The promo videos were for the Anime and the video game, which all of them made me want to get off the couch and go buy the products (especially the video game).  The Conceptual Art was interesting, but it was also a little boring.  It could have used some music or commentary to go with the art.  I did like the fact that each disc had this extra, and it corresponded with the episodes on the disc.
 

Overall

I absolutely LOVE Mafia themed anime series, and Gungrave is the best so far!  The characters are well developed and the plot is pleasantly unpredictable.  For being 26 episodes long, the story unfolded smoothly and was delightful to watch.  Most of the first half of the series was about Brandon Heat, which were my favorite episodes, and the second half was about Beyond the Grave (after Brandon is killed).  I do admit I wasn't hooked by the first episode, which I look for when starting a series, and it wasn't until about the third episode that I was devoted to watching it.  Now, I must warn you that the first episode is about Beyond the Grave, then the second is about a young Brandon Heat.  That is the only problem I have about the series, the first episode almost seemed to be part of the story during the first half, but this feeling is resolved around the time Brandon dies. The ending of the series was Brilliant!  The very last episode wasn't overly depressing and ended the series open ended enough that you knew their world was all right.  Some series end with the ultimate battle, and the world is kinda ruined, and that's where it ends. Well, Gungrave avoided that by developing the future that those destroyed would have left abandoned.  

Gungrave is a relativity quite series, but it's almost vital to the development of the plot and the expression of the real-life aspect of it.  Except for Necrolyzation, the series is totally believable.  I was able to relate with the character and feel what they felt.  
 

The themes were the most intricate part of Gungrave.  The basic themes were Revenge, Loyalty, and Protection of what you care about the most, and a little bit of Friendship.  But, the big theme I found was fighting for your righteousness and discovering what is important to you.  

Those who enjoy series like, Gankutsuou: The Count of Monte Cristo, Baccano!, and Death Note should check Gungrave out. 

ComicsOnline gives Gungrave: The Complete Set, 5 out of 5 Features of a Heavy Weapon filled Coffin.