YMMV / 20th Century Boys

  • Big-Lipped Alligator Moment: The introduction of Keroyon, where the rest of the group screams at his appearance, followed by a full-page spread of a man with a frog's head. Then he turns out to just be an ugly guy.
  • Crazy Awesome: Kenji, after the second time skip.
  • Complete Monster: Both versions of Friend were absolute monsters of a different variety.
    • The first Friend (Fukubei Hattori), after growing up ignored by his classmates, with their attention often focused on Kenji Endou, developed a craving for attention, and a disproportionate hatred for Kenji. Already wicked as a child, he psychologically abused his so-called "best friends," regularly tried to terrify people with his tricks, and ruined the childhood of one of his classmates, who would later become the second Friend thanks in part to the first Friend's cruelty. Forming the "Friendship Party" as an adult, this Friend began developing a virus that painfully killed anyone it infected, all while silencing anyone who got his way. Unleashing the virus, he framed Kenji and his group for the ensuing 150,000 deaths, took over much of the world as a "hero," and ruled it with an iron fist, sending people to reeducation camps for even minor crimes. His master plan is then revealed: Use a new virus to wipe out 99% of the human race, then rule over the remaining 1% of "true believers." Sociopathic, egomanical, and petty, the first Friend set the bar for wickedness in this manga.
    • The Second Friend (Katsumata) grew up unliked and bullied, in particular by the aforementioned first Friend, and this resulted in a hatred for all humanity. Taking over after the previous Friend's death, he destroys much of human civilization with a new virus and rules what's left even harsher than the previous Friend, spreading tales of "aliens" invading to keep innocents terrified in the process. To further cause chaos, this Friend regularly sends out small doses of vaccines to groups of potential rebels, knowing they will tear themselves apart trying to acquire the antidote. Revealing he plans to destroy all of humanity with an incurable virus, this Friend tries to make Kenji watch as he kills Kenji’s niece, Kanna (Kanna’s mother is Kenji’s sister, while her father is the first Friend), as revenge for a transgression Kenji committed against him as a child, and, when finally defeated, it is revealed he left an Anti-Proton bomb to be detonated by his followers, which will destroy the entire world when activated. Though having the aforementioned Freudian Excuse, the second Friend was ultimately a psychopathic misanthrope whose attempted revenge on humankind was Disproportionate Retribution taken to its highest degree.
  • Crowning Music of Awesome: Kenji's song, Bob Lennon. It's a rare in and out of universe example, as a recorded version was released with the volume it was introduced in. Urasawa Naoki can sing, apparently.
  • Ear Worm: Kenji's song, Bob Lennon. As mentioned above, it's a rare in and out of universe example, as it plays a very important role in the plot as the story goes on, especially the 'Gutalala Sudalala' version, which even the characters comment on as being an ear worm and since it was released in real life it can end up being stuck in your head very quickly.
  • It Was His Sled: There are two Friends, and the story goes way past the twentieth century. Surprisingly, Friend's identity is a well kept secret.
  • Hilarious in Hindsight: In one flashback young Kenji and Yukiji argue who makes better sounds - Tetsujin 28 or Giant Robo. In 2004, so very soon after that scene, a new adaptation of Tetsujin was released. In which Tetsujin makes the exact same sound as Giant Robo.
  • Magnificent Bastard: Friend.
  • Nightmare Retardant: A mob of insane cultists swarming Kenji's shop to kidnap Kanna: terrifying. A mob of insane cultists swarming Kenji's shop to kidnap Kanna while chanting "DESTINY'S CHILD": a little goofier for English-speaking audiences.