Trivia for Memoria Freese can be found here.
- Actor-Shared Background: Diego Santos, Bell's Latin American Spanish's voice actor, had no previous experience in voice acting at the time, just like Bell is also a rookie adventurer as well, making Santos a quite fitting role for someone like Bell.
- Completely Different Title: The series is known as ¿Qué tiene de malo intentar ligar en una mazmorra? (What's Wrong with Trying to Flirt in a Dungeon?) in Spain. In Latin America, it was named as DanMachi: ¿Está mal seducir chicas en un calabozo? (DanMachi: It Is Wrong to Seduce Girls in a Dungeon?)
- Darkhorse Casting: Big time in the Latin American Spanish dub: Since the dub was done in collaboration between a professional voice acting studio in Chile (MOVC) and a voice acting academy in Argentina (Hispano Language Advisory), most of the voice actors from the Argentinian side are newcomers, while the Chilean side are voiced by professionals actors instead. This is especially more evident with the both leads, as Bell's voice actor (Diego Santos) is an Argentinian voice actor with no previous roles whatsoever, while Hestia's Chilean one (Lucía Suárez) is an experienced veteran with many roles under her belt, including Harley Quinn and Sweetie.
- Development Gag: Episode 13's title Familia Myth was the working title for the series. It's still displayed in all title cards if you're watching the most common fansub.
- Directed by Cast Member: In the Latin American Spanish dub, Aldo Lumbia is the ADR director as well as the voice actor for Mord Latro and Canoe Belway.
- Genius Bonus: The common language being called Koine is both Shaped Like Itself (Koine is Greek for "common") and this, seeing as the Greek used in the Bible was called Koine Greek in a similar sense.
- International Coproduction: The Latin American Spanish dub was dubbed at Hispano Language Advisory in Argentina and Movc in Chile. The additional voices were provided by students from Córdoba's Academia de Doblaje, also based in Argentina.
- Milestone Celebration:
- The anime marked the 10th anniversary of SB Creative's GA Bunko label along with Nyaruko: Crawling with Love!, Chivalry of a Failed Knight, Hundred, and Undefeated Bahamut Chronicle.
- The mobile game adaptation Memoria Freese celebrated its 1st anniversary in June 2018. This update added a massive game-exclusive storyline called Grand Day written by the original author, which delves into the lore behind the legendary "Three Quests".
- No Dub for You: Zig-zagged in Latin America: Arrow of the Orion got a release on their region of Netflix without a dub, but months later the TV series was released on the platform with dubs in English, Spanish and Portuguese.
- The Other Darrin: In Sword Oratoria, Riveria in Japanese is voiced by Ayako Kawasumi due to Risa Taneda's throat problems on mid 2016. This also applies to Gareth in English, who is voiced by Mark X. Laskowski due to Chris Ayres struggling with COPD throughout 2017 until his death in 2021.
- Portmanteau Series Nickname: DanMachi, from its Japanese title of Dungeon ni Deai wo Motomeru no wa Machigatteiru Darou ka
- Publisher-Chosen Title: While the title was originally used for the story's web novel incarnation, it was submitted for publishing under the title Familia Myth. Fujino Omori's editor reverted the title to its initial one when it was picked up.
- Real-Life Relative: Ryuu and Syr are voiced by Genevieve Simmons and her younger sister Juliet in the English dub.
- What Could Have Been:
- Originally, the author planned for Revis and Alise Lovell to be the same person, but he discarded the idea due to how cruel that would have been to Ryuu.
- In the original drafts of the story, Raul was initially planned to fall in love with the Harpy Xenos, Fia, and eventually be one of the ones who would allow the Xenos to gain acceptance from the surface dwellers. This potential plot point was dropped from the series due of the inclusion of Aki.
