Masashi Kishimoto's Naruto, Tite Kubo's Bleach, and Eiichiro Oda's One Piece are the traditional "Big Three" of shonen anime, and they may be contrasted and compared in a variety of ways. As enduring protagonists, their three separate heroes have a lot in common, including the fact that they all started off facing a villain.
Even the toughest shonen antagonists can be defeated by Naruto, Luffy, and Ichigo by this point, yet in the beginning, even weak antagonists like Higuma the Bear, Fishbone D, and Mizuki were significant. The three heroes could only begin their epic quest and establish their worth by conquering these initial villains; nevertheless, one of these foes distinguishes out from the other two for particular reasons.
Mizuki the Bitter Chunin, the first antagonist in Naruto
In Naruto's first episode, the miserable Naruto Uzumaki failed his final exams yet again and was desperately seeking a way to prove his worth and become a genin. That was when Mizuki, a chunin, pretended to be his friend and asked him to steal a scroll explaining how the Shadow Clone jutsu works. Mizuki then turned on Naruto in the forest that night, and it fell to Iruka Umino, Naruto's teacher, to fight him.
Iruka suffered serious injuries, so Naruto quickly picked up the Shadow Clone jutsu and used it to beat Mizuki nearly to death. Looking back, Mizuki was only a "basic" chunin, with no particular secret jutsu or even distinctive weaponry to use in battle. He was spiteful and self-centered, and he hated Iruka and the Hidden Leaf Village for denying him what he sought through their dubious means. Fans of Naruto were unaware that he had Orochimaru's support at the time.
The first chronological antagonist in One Piece is Higuma The Bear, a mountain bandit.
Most of Monkey D. Luffy's worst enemies in One Piece are either pirates or Marine officers, but Higuma the Bear -- the protagonist's first enemy -- was neither. Higuma was actually a mountain bandit who commanded his own team of thugs, and in One Piece's first chronological storyline, his gang terrorized Luffy's home village in the East Blue.
Higuma was a petty bully and talked a good fight, but he never actually showed any skill with the sword. He only got away with his antics because red-haired Shanks turned the other cheek, and then Higuma tried to kill Luffy in the ocean. That was when a Neptunian emerged and ate Higuma whole, giving Shanks a chance to rescue Luffy at the expense of his left arm.
The first antagonist in Bleach was Fishbone D, a Humanoid Hollow.
Protagonist Ichigo Kurosaki could always see ghosts -- typically harmless Pluses -- but he wasn't yet ready to face a Hollow. In Bleach's world, Hollows are monstrous, mutated souls of the restless dead with a skull mask and a round hole in their chests. Fishbone D was a fairly typical non-Menos Hollow, but it did pose a serious threat to Ichigo, who back then had no means of fighting back.
Fishbone D attacked the Kurosaki family clinic one night and nearly killed Ichigo's family, until the tsundere Soul Reaper Rukia Kuchiki arrived to fight it. Rukia got hurt so she gave her powers to Ichigo, awakening his own latent spirit powers in the process. Ichigo then obtained a nameless zanpakuto and slew Fishbone D with it, launching his career as a substitute Soul Reaper.
Higuma from One Piece is among the top Big Three starter villains.
Higuma the Bear was Luffy's first villain chronologically in One Piece, and was also the most thematic within the "East Blue" saga. Unlike Naruto's Mizuki, who was a petty ninja, or Bleach's Fishbone D which was merely a monster, Higuma existed to antagonize the hero as well as establish a theme. Piracy is a major threat in One Piece's world, but even pirates themselves face many hazards on the high seas -- and Higuma learned that the hard way.
Higuma, who was more used to the mountains, grossly underestimated the high seas and how much they can toughen up a pirate crew like Shanks's. Symbolically, the villain quickly died when he ventured onto the sea to kill Luffy, proving the ocean is a test that not everyone can pass. There's a tough barrier of entry just to be a pirate at all in One Piece, which gave Luffy a serious challenge to overcome in the coming years. Higuma's death was a warning, but as the shonen hero, Luffy was eventually ready for what lay ahead.
While Higuma was aggressive and confrontational as a petty bully, he was ultimately weak. By contrast, Shanks turned the other cheek several times, prompting Higuma to look down on him as a coward. However, Shanks was the wiser man by not rising to the villain's bait, showing restraint and discipline. The tables were turned when Shanks finally fought back, far away from the innocent villagers. This shattered Higuma's illusions about his own strength and the apparent cowardice of pirates. In short, Higuma existed to contrast with the ocean and Shanks, giving his life to illustrate what the sea and real pirate captains are really like. That makes him the best Big Three starter villain.