Garo/Trivia
- The Danza: Rei Suzumura is portrayed by Ray (pronounced the same) Fujita.
- Hey, It's That Guy!: Gonza is played Yukijiro Hotaru AKA Inspector Osako.
- Nao Oikawa, who goes from being a popular porn star, to a one-shot role as a MotW in this show, to part of the Quirky Miniboss Squad in Engine Sentai Go-onger.
- Karma from Red Requiem is another AV idol, Saori Hara.
- Also of note is that the actors portraying Kaoru, Rei and Rei's deceased girlfriend have all been in villain roles in Kamen Rider Blade, Kamen Rider Faiz and Pretty Guardian Sailor Moon respectively. Kouga's father would later be Kamen Rider Ga-Oh, Tsubasa Yamagatana/DAN would later be Kamen Rider Rey AND Saga, and Kaoru's friend Asami would later be Geki Yellow.
- Kaoru's father was the CEO of Smart Brain before he decided to become painter
- Kurusu in the Red Requiem movie is played by Shinji Kasahara AKA Naoto Takizawa/Time Fire
- In the same movie Shiguto is played by Masahiro Kuranuki, or Sion/Time Green
- Two supporting characters in different episodes are Kitaoka Shuichi/Zolda and his butler Gorou.
- Masato Kusaka/Kamen Rider Kaixa appears in an episode of Makai Senki.
- Jin-san makes manhole covers in his spare time.
- An old couple found a way to bring Tezuka Miyuki/Raia back from the dead. Kind of.
- Jiro turns into a blue wolf in a different way now.
- Leo's father in Makai Senki is played by Daisuke Ban, perhaps better known as the eponymous heroes of both Kikaider and Inazuman.
- Ganon's humanoid form is played by transvestite actor Shinnosuke Ikehata AKA Peter, who was famous for playing Kyoami, The Fool in Akira Kurosawa's Ran.
- Nao Oikawa, who goes from being a popular porn star, to a one-shot role as a MotW in this show, to part of the Quirky Miniboss Squad in Engine Sentai Go-onger.
- Hey, It's That Voice!: Ai Orikasa not only provides the voice of Rei's familiar/amulet Silva, but she also shows up in person when Silva appears in human form in the gaiden episode "Smile".
- Along with Hironobu Kageyama, who's been voicing Zaruba AND singing the theme song.
- Name's the Same: Makai Senki #8 has a cursed samurai from ancient times called Juuzou. And #9 has a bitter old actor named Ryuunosuke, who even does a Wholesome Crossdresser act at one point.