- Bonus Material: At the end of each chapter in the compiled volumes, there's a panel that works as an epilogue and humorous off-panel thoughts (from the characters or the author himself) about its events.
- First Appearance: Some characters and Saiki's (basic) psychic powers were introduced in the seven original one-shots of the series. These one-shots were later compiled in Chounouryokusha Saiki Kusuo no PSI Nan, also referred as "Volume Zero".
- In chapter 14, Saiki briefly mentions that he is an acquaintance of the illusionist Uryoku Chouno and Michael (his assistant), since they first appeared in one of the original one-shot chapters. This got corrected in the TV anime adaptation's chronology, when it adapted their first interaction.
- Marth Debuted in "Smash Bros.": Although the manga has yet to receive a localization outside of Japan, Saiki himself appeared in a few other pieces of media before the 2016 anime was licensed in the U.S.
- Saiki's first official Western debut was in a crossover chapter that was localized and included within the second volume of Assassination Classroom, where it was given a first possible English title: "The Mishaps of Kusuo Saiki".
- Saiki also appeared as a playable character in J Stars Victory VS, a Massive Multiplayer Crossover game that was released outside of Japan in 2015.
- No Dub for You: A very infuriating example in the Latin American Spanish version in Netflix: The TV series lacks a dub in that region, despite having a official Spanish name, something that almost every original Netflix anime series broadcasted there (with the sole exceptions of The Seven Deadly Sins and Bayonetta: Bloody Fate) lacks, and not to mention it was broadcasted without previous warning or promotion.
- No Export for You: While currently averted with the TV anime note , the manga (and the light novels) remain only available in Japan.
- The Other Darrin: The anime cast is entirely different to that of the VOMIC and the web-anime adaptation.
- Real-Life Relative: The Japanese voice actors for Saiki's married relatives are real-life married couples.
- Talking to Himself: Daisuke Ono (Sub) and David Wald (Dub) voices Nendou and both of his parents because they look alike.
Trivia / The Disastrous Life of Saiki K.