Ditzy Genius / Anime & Manga

• Asteroid in Love: Ao is usually sensible and intelligent, but her relatively frequent lapse of common sense puts her to this trope, mainly due her interest in astronomy as well of her Spock-ish way of thinking.
• Kirino Chiba of Bamboo Blade is frequently behaving in a ditzy, overexcited manner. She is also ranked 20th in her year at school. Not genius level, but highly respectable nonetheless.
• Bartender: The titular character, Ryu Sasakura, is a textbook example. Behind the bar, he is The Glass of the Gods, a walking liquor encyclopedia and the king of customer service, smooth as silk and slick as a silver bullet. Outside his comfort zone, he is a somewhat goofy Manchild with a strange obsession with eating gyoza.
• In Beauty and the Feast, Yamato is mentioned to have excelled at any sport he put his mind to and was even chosen to represent Japan at a junior high level baseball tournament. But he's also air-headed and spacey, often forgetting to respond to his family's texts and failing to communicate himself properly, causing others to make assumptions about him.
• Bleach: Orihime is a dorky, clumsy and airheaded cloudcuckoolander... and one of the top scoring students in her class. Justified in that, while she lives alone, she's financially supported by a distant aunt on the condition that she gets good grades in school. If she didn't do half as well in school as she does, she would've probably ended up homeless years ago.
• Case Closed:
  • Teen Genius Hattori Heiji is a brilliant detective who always keeps on par with Shin'ichi's deductions, but can't for the life of him remember to call Shin'ichi "Conan" when they're in public (which shouldn't be that hard, since "Conan" was the first name Heiji knew him by). He also has a bit of a Hair-Trigger Temper, particularly when talking to his childhood friend Kazuha. So much so that one fanfiction diagnosed Heiji with Asperger's Syndrome in a fictionalized psych profile.
  • The main protagonist, Shin'ichi Kudo, is introduced as an amazing detective, even given the nickname "The Modern Holmes". However, he is incredibly socially inept, which was a major reason why he had little to no friends as a child, the sole exception being Ran.
• A Certain Scientific Railgun: Harumi Kiyama is a very intelligent scientist, but lacks even the most basic shred of common sense. For example, her thought process when it's hot essentially comes down to "It's hot, therefore I should take off some clothes." The fact that she's doing this in public doesn't occur to her. She actually becomes the source of an Urban Legend about a "Stripper Lady" because of this.
• Lloyd in Code Geass. Brilliant mecha designer, does not understand basic human interaction. The characters are shocked to hear that he is engaged. It's an arranged marriage since Lloyd is an Earl. He was only interested in the match because of his fiancee's vintage Giant Robot.
• Death Note: L is a Ditzy Genius (compared to Misa Amane) as he was stated by the author of Death Note to be the most intelligent character in the series, and has enough idiosyncrasies and few enough social skills that he can barely interact. Generally hyper-competent, he tends to fail in normal conversations and interpersonal relations.
• Delicious in Dungeon:
  • Laios is incredibly knowledgeable about monsters, surprisingly good at deduction and observation, a decent tactician, and a peerless fighter. He also once tried (successfully!) to eat Animated Armor. On the other hand, he often lacks common sense and is utterly oblivious to any kind of social cues.
  • Senshi is a keen survivalist, a solid combatant, and a Supreme Chef, but spending years underground and eating monsters makes him fairly spacey and dotty. After being kidnapped by orcs and claiming to have a plan, he revealed his plan was that he could use the orc supplies to make bread.
• Doraemon: Although Doraemon is the smartest of the main characters and seems to have a vast knowledge of many different subjects, he ended up the clumsiest of his kind due to a problem during his production, and will rarely get anything done when he's nervous.
• Dragon Ball:
  • Bulma, especially in the English dub. She's one of the brightest minds in the world, being able to make brilliant inventions out of junk in minutes, however, she tends to make bad judgement calls. This is best shown in the Red Ribbon Army Saga where she invents a high-tech spy drone and sees that Goku is planning to attack the Red Ribbon Army HQ. After the drone gets blown up she realizes they need to call for help, but she complains they don't have a phone. Turtle then points out that if she could make a drone then a phone shouldn't be any trouble for her, to which she gets the point and sets to work making the phone. All this and yet somehow she gets the idea to become a treasure hunter. She gets only slightly better at this over the course of the series, in the sense that she doesn't walk headlong into danger without thinking first so much.
  • It runs in the family, because her father, Dr. Briefs, is even worse — he's a genius in anything mechanical, but has absolutely no common sense.
  • While Piccolo is easily the smartest of the Z-Fighters and a good tactical genius, several of his battle plans fail because he overlooks glaring flaws in them and doesn't notice until it's too late for him to do anything about it. For example, when fighting Raditz, he breaks out the Special Beam Cannon to take him down, but it fails the first time because he didn't actually think to immobilize Raditz beforehand.
• Girls und Panzer: Miho Nishizumi. At first glance, she's shy, socially awkward, and usually clumsy. She is also an expert tactician and commander in the sport of Sensha-do/Tankery, due to being from one of the most prominent families in the sport. The only thing that sets Miho apart from her family is that Miho values the safety and efforts of her team which clashes with her family's "win at all costs" belief.
• GUN×SWORD: Joshua Lundgren is one of the greatest mecha engineers in the world... and doesn't understand why women scream when a guy walks into the girl's bathroom.
• Hayate the Combat Butler: Maria and Nagi have both skipped grades and know multiple languages. When they are split up while on a train, Hayate is torn between protecting his master or staying with the maid until Hinagiku shows up for a less-than-fully-heroic rescue because they are completely clueless about the world.
• Hidamari Sketch: Miyako acts like she has a case of Attention Deficit... Ooh, Shiny!, but her artistic and academic abilities are levels above the other characters—she's one of the few people who is Brilliant, but Lazy but not Book Dumb. That said, her use of Gratuitous English is also quite terrible...
• Umaru Doma from Himouto! Umaru-chan tends to be this, especially at home where she shows her true personality as a childish Otaku; while she gets perfect grades and is good at everything she does at school, in private she's a lazy, immature slacker who doesn't even know what an Internet router is (which, of course, she finds out the hard way—by accidentally spilling cola on it).
• Kaguya-sama: Love Is War:
  • Most of the humor in the series comes from Kaguya and Miyuki being this: they're legitimately very bright, but they also suffer from badly warped ideals, weird upbringings, and Complexity Addiction, resulting in them turning every single exchange into a Battle of Wits. Most of these "battles" end in a stalemate because of them managing to outsmart themselves. Kaguya, for instance, nearly had Miyuki dead to rights in an exchange that would have ended in him admitting he was a virgin, but revealed in the process that she was so sheltered about sex that she thought "your first time" meant kissing.
  • It becomes clear as the series goes on that Fujiwara is more flaky than stupid, which isn't helped by her "best friends" sabotaging her test scores by tricking her into not studying. She can speak five languages, design functional games, elaborate scams, is a skilled pianist, and still scores slightly better than average on tests in a very difficult school despite almost never studying.
• Love, Chunibyo & Other Delusions!: Sanae Dekomori from the anime adaptation may be a Cloudcuckoolander out of her delusions, but she's still the top student of her grade, to Yuuta and Shinka's utter surprise.
• Lucky Star: Miyuki Takara is extremely smart, talented, gets very high grades, and has a lot of knowledge about different subjects that the other three main characters don't. However, she can be rather clumsy and naive, and is prone to spacing out when she's thinking too much about something. That's probably why Konata is always saying how Moe she is.
• Monthly Girls' Nozaki-kun: Yuu Kashima is good at almost everything, but she has an off-kilter thought process and can never seem to figure out when the things she does will get her in trouble.
• My Hero Academia: Denki Kaminari. He is considered the dumbest person in class 1-A, but at the beginning of the story we are told that UA is the top Hero school in Japan and perhaps the entire world, and that in order to get in you basically had to ace middle school, showing that literally everyone at UA who is considered "dumb" such as Mina Ashido, Rikido Sato, Tetsutestsu Tetsutestu, and Ejiro Kirishima, are actually all still quite intelligent. Denki is a special case as he does have many real moments of stupidity, but he's still at the top school in the world meaning he is simply the dumbest genius in a school of geniuses.
• Nichijou: Professor Shinonome is a technological wunderkind who built a Ridiculously Human Robot and a device that allows her cat to speak like a human. She's also eight years old and possesses all the naivete of a kid her age despite her amazing mechanical aptitude, on top of having a rather short attention span and rarely ever thinking about the consequences of her actions.
• Ouran High School Host Club: Tamaki Suoh is so ditzy that despite starting a Host Club, he mistakes his romantic feelings for Haruhi as wanting to be her father. He also has the second-highest grades in his year without even trying, to the frustration of some.
• Pokémon Adventures: Black. Type match-ups, move accuracy, evolutionary lines, detailed information on every Gym Leader and Elite Four member (including their team line-ups), Black studied them all before going out on his quest To Be a Master. Pity he has No Social Skills and feels that it's appropriate to shout out his dreams to people who are quickly going deaf.
• Saiyuki: In Gaiden, Tenpou is shown to be a brilliant strategist, but seems baffled by everyday life and would probably be buried under a pile of books almost permanently if it wasn't for Kenren.
• Sekirei:
  • Mikogami Hayato graduated from college before the age of 15 and is cunning enough to outsmart the resident Manipulative Bastard. On the other hand, he's a hyperactive teenager prone to Attention Deficit... Ooh, Shiny! moments. He treats the Sekirei Plan like a super-exciting game of Pokémon and expresses the desire to transform the world into something out of a video game if he wins.
  • Big Bad Minaka Hiroto was also this before he became The Wonka.
• Sleepy Princess in the Demon Castle: When properly motivated, Princess Syalis is scarily competent; she breaks out of her cell so easily that the demons eventually give up on locking her in, she repeatedly manages to MacGyver sleep aids out of random objects, and it's eventually revealed that she's a well-practiced bureaucrat who's capable of keeping the castle running just as well as (if not better than) the Demon King. However, she also has a tendency for extreme tunnel vision; getting so focused on her objective that she disregards most of the consequences of her actions, causing her to border on both Lethally Stupid (her attempt to use magic as a sleep aid ended up knocking out everyone in the castle except herself) and Too Dumb to Live (using a lethally poisonous mushroom as an impromptu mattress, repeatedly).
• Space☆Dandy: Dr. Gel is said to be the Gogol Empire's greatest scientist, and is even shown building impressive technology and performing complex calculations and equations to back this claim. That said, he suffers from Skewed Priorities and repeatedly fails at his assigned task of capturing the title character. He's so bad at it, in fact, that Dandy doesn't even know that Gel exists until the final episode. Gel simply assumes that everything Dandy does is an ingenious plot to foil him, and while Dandy is smarter than he looks, Gel's repeated failures can usually be chalked up to bad luck and cartoonish incompetence.
• Tomica Hyper Rescue Drive Head Kidou Kyuukyuu Keisatsu: Jou Kurumada. He's a skilled mechanic and brilliant strategist. Other than that, he can be rather clueless. The drama of an entire episode is drawn from the fact that he can't remember the contents of a phone call he had with his wife just the other day.
• Yuyushiki: Yui sees Yuzuko as this. She does do well in school, but as Yui points out...
  Yui: [on Yuzuko's defying Smart People Wear Glasses] She really is pretty smart. It's her ideas that are dumb.