- Actor Allusion: When Ishigami mentions that he has plans over Christmas, Fujiwara assumes that he'll be busy playing video games or watching Pretty Cure. Fujiwara's seiyuu is the voice of Cure Milky.
- Adaptational Context Change: In the anime, there was an extra scene during the psychological test chapter where Hayasaka wears a paper cutout of Fujiwara's face so Kaguya has someone to practice one of her schemes against. The manga would eventually use a similar visual where she's talking to Kaguya while wearing a Shirogane mask, though there she's secretly acting as an intermediary between her and Shirogane by relaying questions and answers to him via text message, allowing the two of them to unknowingly be completely honest with each other for the first time.
- Casting Gag: Kaguya's voice actor Aoi Koga appears in the live-action film as a theatre employee.
- Creator's Favorite: According to an interview, Aka says that it's Shirogane.
- Fan Nickname:
- Kaguya's dere side is referred to as "Bakaguya" and her cold side is called "Iceguya" or "Kuuguya".
- Shirogane is called "Monster Virgin".
- Fujiwara is referred to as "Subject F", "(Mistress) Cuddlebuns", "Cotton Candy 2.0", and "Super High School Level/Ultimate Black Ribbon". Whenever she does something or thinks about something traitorous she's called "Natural Born Traitor". She's also called "Mommy" or "Fujimama" whenever she's teaching Shirogane.
- Ishigami is called "Our Guy", "mah boy" or "mah man".
- Maki was called "Stalker-chan" prior to her name being revealed. She also earned the title "Our Girl" after developing a close relationship with Ishigami. Ishigami's nickname for her, "Tsundere-senpai" is also occasionally used.
- Miko is occasionally referred to as "Lino" due to people having mistaken the upper case I in her name for a lower case L (since the fan translations using a sans serif font). People would later embrace it and claim that it was a Portmanteau for "Lewd Iino".
- Because Touhou Project also has a filthy rich black-haired Kaguya and a light-haired Fujiwara, Kaguya and Chika are also known as "Teruyo" and "Mokou".
- Kashiwagi is known as "Kashiwagi's Boyfriend's Girlfriend", a carryover from when Tsubasa was only known as "Kashiwagi's Boyfriend".
- Thanks to being voiced by Takehito Koyasu in the anime, Papa Shirogane is called "Papa DIO". Jokes about Shirogane being related to Giorno popped up as well.
- Milestone Celebration: The announcement for the anime came out the same week as chapter 100note
- Name's the Same: Shirogane's younger sister Kei has same name as Shiroe's real name.
- Promoted Fanboy: The author for the ero spin-off, Sakayama Shinta, actually drew two hentai doujins based on the series.
- Sleeper Hit: It's one the most popular romance manga in the world -having sold over 3.5 million copies before the anime even aired- despite lacking the fanservice and harem elements that most of its contemporaries have.
- The Wiki Rule: Kaguya-sama wa Kokurasetai Wiki
- Working Title: The series was originally going to be published as "IQ" (愛求 Aikyuu lit. Love Seeking / Love Longing) in Japan.
Trivia / Kaguya-sama: Love Is War