All spoilers are marked with strikethroughs. Caution advised while reading.
Grappler Baki isn't that complex of an Anime. In fact, it is one of the more simpler ones with a very little story to it, and with an enhanced focus on action. While other anime such as Dragon Ball Z or Yu Yu Hakusho at least had a somewhat feasible backstory to them which made the anime worth watching even if you took out all the amazing action and hype from it, Grappler Baki doesn't really seem to have much of a basis in much of anything. Luckily, though, the anime isn't as much of an action-oriented mess like Black Lagoon from the anime that I can name and is more or less barely watchable with a few factors which keep you watching it even if things might seem to get a little flat.
I haven't watched much anime, but I'd say that the art and animation is more or less below average for the time when it was produced and that the same would go for its sound as well. By modern contexts, they pretty much suck with the animation being choppy, the art blurry and pasty, and the sound flat and boring. They would've probably had done a much better job by using songs available under Free Licenses for their opening and ending themes. There are only two saving graces for the anime,
1. The dark undertone of the anime can be felt from the very beginning which leaves you uncertain whether there will be a happy ending to it and makes you watch to find out for yourself.
2. The martial arts that are shown in the anime have been quite well researched and presented in realistic or exaggerated terms in what they were meant to be. This point isn't really true for the first season of Grappler Baki, but rather the second season. However, as far as things go in the first season, there is a lot of content which is quite unrealistic. But then again, when have we watched anime for its realism. And in the face of most other anime fo the genre, it is comparatively surprisingly realistic.
Apart from that, there is a very simple backstory to the anime and the story isn't tied together all too well with events just occurring over time arbitrarily. Not to mention that the dialogues aren't the most innovate lines that one can think of...
Grappler Baki is based on the notion that in the root of masculinity lies the desire to be the strongest man in the entire world and while most people lose it or replace it over time, there are a select few remaining who still strive to be the strongest in the world. These people are supposed to be known as Grapplers even though that means something completely different when taking martial arts into context, especially considering the fact that there is little to no grappling to be found throughout the anime.
The anime opens with a scene displaying the brawling prowess of Baki and his desire to become the greatest fighter on Earth when he walks up to challenge one hundred men to a fight... Alone. If you think that's crazy, you've got another thing coming as the anime only gets even crazier as it keeps progressing.
He has the support of a cop who tries to guide him towards the right path and keeps him away from prison and trouble. He is seen as a lonely, young, troubled teen who has no friends and tons of enemies which he has made on his path towards being the 'ultimate man' as per the theme of the anime. His only motivation to become the strongest in the world is to attain his mother's approval, who has more or less rejected him since she's infatuated with his father Hanma Yuujiro, who has rejected Baki for his lack of strength and ruthlessness as a member of the Hanma family. He hence wishes to gain his mother's love by becoming stronger than his father and dethroning him. It's all a big play on the Oedipus complex, to be honest.
The show also features the past of his father, who was a wild beast in his own regard. A ruthless member of the military, Baki's newly married mother fancies him at a party and he seems to take a liking to her. He would later appear in her quarters in front of her husband, kill him, impregnate her with Baki, and then leave. She falls in love with the beast and lies to the cops about Yuujiro, essentially making Baki an illegitimate child conceived in the shadow of murder. I hope you're pretty intrigued by the story thus far...
While that's the backstory to the anime, that's pretty much all the story you'll be getting until the end of season 2. There's a slight twist to the story at the end of Season 1, but it changes effectively nothing.
Baki keeps on chasing his ambitions to defeat his father and goes through a wide variety of training to achieve it, starting off by following his father's footsteps and training in the jungles where he tosses himself off a cliff in order to achieve control over endorphins (essentially natural painkillers in real life but a fighting boost in the anime) and fights a fictional beast called the Yasha where he learns perhaps his favourite signature move which he'll end up carrying with throughout his journey all the way till the end of season 2. In case you're wondering, it is a kick to the groin...
He then goes on to fight a member of the Yakuza who apparently cannot fight, which came as a surprise to me because I thought that Baki couldn't fight when I first saw him fighting, but can grab you so hard he can tear apart the muscles in your body.
He also goes on to fight a team of guerilla soldiers deployed in a forest where he learns to control Adrenaline.
He would then finally go up against his father, who's more or less curious about the powers of a Hanma awakening in his son. He has also lost all affection for Baki's mother at this point since she gave birth to a weak son. By this point, Baki has grown quite strong and even his technique has drastically refined over time. He finally faces his father and gets defeated in battle. His father, disappointed in him, decides to kill Baki when his mother steps in to save her child, acting as a mother for the first time since she gave birth to him. Yuujiro decides to spare Baki by killing the woman who gave birth to his son instead. Baki wakes up to this and finds himself devastated. And here's the subtle shift in Baki's motivations for defeating his father. Instead of wishing for his mother's approval, he now wants to kill his father to avenge his mother instead.
The rest of the anime is Baki travelling around the world, trying to find some challenging opponents to grow stronger than ever before and kicking even more people in the groin. This continues until he stumbles on to an underground tournament held in Japan without any rules where the strongest of the world from various disciplines battle it out to determine the one person who's the strongest in the world. Even though everybody knows that the strongest person is, without a doubt, Hanma Yuujiro...
The rest is the tale of Season 2. But as far as Season 1 is concerned, there is a lot of explicit violence portrayed in very dark and brutal manners. Baki's fighting style remains wild and unrefined for the most part until his fight against Yuujiro, which leads me to wonder about what brought on the sudden change. At least the action is more or less streamline and the animation displays every single aspect of the action, no matter how brutal. There is an undertone which is more of a hybrid between trying to be badass and grossly overshooting and being a cold-blooded killer. But I suppose that's just the spirit of those that are ready to sacrifice everything in order to achieve their dreams of being the strongest in the world.
The usual Shounen theme of the protagonist being kind and warm is present with Baki as well, as he continues to turn defeated enemies into strong allies with his charm and optimistic outlook on the world (Even though that's never really shown in the anime). This includes the Yasha Ape even though Baki supposedly turned his Avocados into Guacamole given the number of kicks he threw there.
Anyhow, that's Grappler Baki for you. At least, the first season. But despite all the criticism and the effort and budget (or lack thereof) put into the anime, it's still good enough for a casual watch in my opinion. If you're fine with explicit violence and demented ways of life, that is...