- Absentee Actor: Kimihito does not appear at all in chapters 43 and 50.
- The Danza: A stealth case, with Miia being voiced by Sora Amamiya.
- Fan Nickname:
- Kii's giant form is called "Regitree" due to resembling Regigigas and the Regi trio from Pokémon.
- Miia's mother is, unsurprisingly, known as Mama Miia.
- After a number of unfortunate Never Live It Down moments, Mero has been saddled with the title of "murdermaid". She's also been saddled by the nickname "Cucklefish".
- Kimihito is occasionally called "Darling" even by the fans, joking on the fact that no one ever calls him by his name in the series.
- The creator himself, Okayado, is nicknamed "Crabman" because his Author Avatar is a hermit crab.
- Follow the Leader: this show launched a whole series of popular 'monster girl' shows following a couple of years later (about the time it takes to get an anime up and running).
- I Knew It!: Many predicted that the anime would be released in June 2017 according to the March 2017 newsletter, given that Sentai releases their works four months in advance. They were right.
- Recycled Script: Chapter 16 is basically a rehashing of chapter 12. Except Centorea is the jealous one instead of Miia.
- Relationship Voice Actor: Junji Majima and Sora Amamiya have been in a series together before, though this time they're not trying to kill each other.
- Sleeper Hit: Tops the N.Y. Times best sellers list, in its first week. And stayed there for its second week.
- What Could Have Been:
- As revealed by Volume 4's omake, Papi was originally designed to have tail feathers on her buttocks. But because of complications from human fashion (i.e. panties folding up tail feathers), the tail feathers are discarded in favour of a humanoid butt.
- Early sketches of Lala show her having red eyes and a regular skin tone color (the dullahan from Okayado's porn strips had regular skin color as well). She looked too much like a normal human person, so Okayado colored her blue.
- Kimihito had no face in his original design. Okayado states this would've been to better emulate the Featureless Protagonist common in Dating games(Kimihito's nickname of "Darling" being another such reference to the genre). The frequent use of Blank White Eyes being an internal compromise for Okayado, deciding that if he was going to give him a face then he would at least avoid drawing his eyes.
Trivia / Daily Life with Monster Girl