For all the bombastic fight scenes shonen anime have, it's nice to know that there are plenty of smarter characters who don't rush in and risk everything. It's not a slight against characters who do, and it can just be a welcome change of pace when a character uses their brain instead of their muscles to solve a problem.
From the villainous Light Yagami to the brilliant but lazy Shikamaru Nara, intelligence goes on a spectrum within shonen anime characters. This means that different characters are intelligent in their own ways, but some tend to be more prepared or otherwise more innovative in their particular universes.
Note: This article will contain spoilers for all the shonen anime involved. It's also just the author's opinion.
Ten most brilliant shonen anime characters ranked on intelligence
10) Kusuke Saiki
The only drawback to this genius is his sadism and ultra-competitive nature. Kusuke is very deceitful and selfish, which never bodes well for Kusuo or their family.
To say that Kusuke's experiments often lead to disaster is about as obvious as Kusuo wanting to have a nice, peaceful life! That said, the former did invent several useful devices, including Kusuo's hairpin-like limiters, a robot replica of himself (which ended up destroyed), and a robot cat named Warp for his parents' 22nd wedding anniversary.
9) Winry Rockbell
Mechanics are not everyone's strong suit, especially automail in the shonen anime Fullmetal Alchemist. Having an excellent mechanic like Winry Rockbell on hand can do wonders for anyone depending on automail prosthetics like Ed and Alphonse.
Winry may be working class, but she's a genius mechanic with an almost otaku-like zeal for automail and its repair and maintenance.
In addition to helping Edward build a complex pair of limbs to replace his missing ones at the age of 11, she's also a very talented and knowledgeable surgeon. Winry was able to help Edward and Al comprehend the alchemical texts when they were young with ease, even helping deliver Ridel and Satella's child!
8) Shikamaru Nara
Brilliant but lazy are Shikamaru Nara's words to live by. Despite the ever apparent laziness and not wanting to do anything troublesome, he has more than proven himself on and off the field in the shonen anime Naruto.
Despite poor grades at the Academy, Shikamaru was the only one of the Konoha 11 to reach the Chunin rank during the first part of Naruto. Despite being newly minted, he was able to stand up to threats like Tayuya of the Sound Four in Naruto and even fully trick, trap, and defeat the immortal Hidan in Shippuden.
Shikamaru's intelligence extends to genius levels, having enough intelligence and forethought to think ten moves ahead of his opponents and devise well over 100 strategies. Said strategies usually involve layers of misdirection and feints to ensnare an opponent, like when Hidan was entrapped and buried after falling for Shikamaru's trap.
7) Bulma Briefs
Like Winry, Bulma is a mechanical genius who can easily understand and decipher alien technology. Bulma created a time machine in Trunk's bleak future, but her most significant and valuable contribution was the invention of the Dragon Radar that detects Dragon Balls.
More examples can be found in that Bulma helped fix Jaco's spaceship at just five years old. She is great at recreating Saiyan Battle armor, even though that's years ahead of Earth tech.
She has also created many of the training equipment Vegeta and Trunks use, picked up Android 17 and 16's blueprints, and is a great, if hotshot, pilot able to perform many complex and daring maneuvers at supersonic speeds even in large airplanes and underwater.
6) Medusa Gorgon
Medusa Gorgon shines above most others as a genius scientist who managed to create a prototypical ultimate weapon out of Crona, her child. Crona's terrible childhood and Medusa's awful parenthood aside, Medusa invented Black Blood, capable of inducing Madness in all it touches.
For an example, look at Crona, a powerful weapon but an emotional and mental wreck, thanks to it! Likewise, Medusa was able to fuse the demon weapon Ragnarok with Crona, which wasn't an easy feat.
Her keen eye for manipulation fooled many at DWMA (Death Weapon Meister Academy) and even Death himself into believing she was just a humble nurse. A humble nurse wanting to curse everyone with Black Blood, but still.
She is capable of bending anyone to her will with various methods of false kindness to torture!
5) Kyudai Garaki
Experimenting on children to develop the ultimate weapon? Pedestrian, says the immoral Doctor Kyudai Garaki from the shonen anime My Hero Academia. This Dr. Eggman lookalike has created life from death with Nomu.
Not only that, but he was able to copy countless Quirks to implant into said Nomu, All For One, and Nine. Likewise, he could also replicate the Quirk Destroying Bullets, giving the League of Villains quite the edge.
Like Medusa, Kyudai has an incredibly kind public persona as the well-respected and championed chairman of Jaku General Hospital. To the rest of the world, he's simply a good doctor trying to devote his life to medical research.
This is useful to hide his affiliation with All For One and is only thwarted when the Pro Heroes raid his hideout. As an aside, the mad doctor was also responsible for restoring Dabi, Tomura Shigaraki's rebirth, All for One's personal recovery, Nine's condition, and Tomura's ultimate state. He even turned the hero formerly known as Loud Cloud into the villainous Kurogiri.
4) Light Yagami
No list of shonen anime geniuses' is complete without one or two extra villain protagonists like Light Yagami! The wielder of the Death Note in the shonen anime of the same name, Light is on here because he's an older teen in high school and considered a natural genius.
This ambition caused him to keep going ahead with his "Become God" plan. He was able to outmaneuver and outfox anyone who tried to get at Kira.
From creating false bottoms in his desk to relinquishing his memories, Light had a great run as a villain. The only problem is he was still only human and was subject to so much hubris that it was inevitable that he'd fall.
Even evil geniuses get caught in the end, as even Kyudai was arrested when the heroes raided his laboratory.
3) Conan Edogawa
Speaking of geniuses putting evil away, Conan Edogawa, aka Shinichi Kudo, of the murder mystery shonen anime Case Closed/Detective Conan, is above even Light Yagami. Even if he's stuck in a kid's body, he always gets his perp.
Of course, having a kid's body isn't all that ideal for a detective, so he usually tries to get disgraced detective Kogoro Mouri to become famous to attract related cases to those that poisoned him.
Conan's detective skills include a photographic memory, extensive knowledge of many subjects, keen observation, paranoia senses (think Spider-Man's spider-sense), and quickly telling if someone is bluffing or lying. His strategies can rival Light's in their complexity since he has tricked people into confessing in multiple ways.
2) Sōsuke Aizen
When you are responsible for replacing the government, multiple deaths (including faking your own), and are such an iconic villain that fans think the shonen anime Bleach peaked after you died, how can you not make such a list? It'd be dire if Sōsuke Aizen were left off!
Despite appearing as a soft-spoken man at first, Aizen is dangerously manipulative and always one or three steps ahead of nearly everyone, including Ulquiorra Cifer and fellow co-conspirator Gin Ichimaru.
His true objective of toppling the Soul King wasn't revealed until he let it be, and his arrogance only grew as he continued to gain power and manipulate everyone. Even after Kurosaki Ichigo managed to stop him, Aizen was revived to aid Ichigo in fighting Yhwach, who threatened all three planes of existence.
After all, what good is a king if there's no kingdom?
1) Senku Ishigami
So, all of these other people? They've had support, sound and well-mannered places to go, and even shelter. What happens when you're one of the only people left alive on Earth after a virus has crippled the human population and tasked yourself with restoring the human race?
That's the question Senku Ishigami tries to answer in the post-apocalyptic shonen anime, Dr. Stone.
While not physically capable of fighting, Senku is arguably the most intelligent of shonen anime characters since he's got an encyclopedic knowledge of all things scientific.
He was able to easily create the de-petrification elixir despite the limited tools and resources on hand. He's got an eidetic memory, great tactical intelligence to end a war without bloodshed, mental resilience tough enough to last nearly four millennia, and great linguistic proficiency.