- Fan Work Ban: Just like all Sanrio titles and characters, fan work of the Sanrio Boys is banned to protect the characters' image. The biannual Comic Market also bans any unofficial Sanrio work from being sold.
- I Knew It!:
- Episode 11 of the anime had Badtz-Maru and Keroppi on the episode preview. Subaru and Naoki would appear in the final episode, as information about their voice actors leaked.
- Considering how popular some of Sanrio's other big stars are, people were speculating who would be associated with characters like Pochacco, Tuxedo Sam, Kuromi, and Kirimi-chan. The 2018 Miracle☆Stage play introduced boys specifically for these mascots, though it sadly Jossed the fanon plot of Yuri becoming a Kuromi fannote in the process.
Trivia / Sanrio Boys