- Sailor Moon:
- Doesn't a certain shot◊ from the opening look familiar?
- Not only are the Defense Club's costumes Sailor Moon parodies, but so are the Conquest Club's◊, with the bling massively amped up.
- In one chapter of the Conquest Club manga, everyone tries to recall their first meeting with Zundar. Akoya's "flashback" is basically the boy version of Usagi meeting Luna.
- Taken up another notch in Season 2. Yumoto's new attacks, True Love Attack and True Love Fountain are very similar in appearance to Moon Spiral Heart Attack. He even did the spinning pose!
- After getting their Lovracelets, Yumoto wonders if that's like The Wombat Returns.
- Episode 3 features a poster that looks like it came straight out of Free!. It, aside from showing up in episode 3 as the preview suggested, also shows up in episode 2◊ as Foreshadowing.
- The arm wrestling scene in episode 3 looks awfully familiar. Who'd have thought that a Stallone reference would make it into a magical boys show?
- Episode 3 has a huge Princess Tutu vibe, what with ballet dancers transforming into birds, the heroes helping characters get in touch with their emotions and more pirouettes than you can shake a (love?) stick at.
- In Episode 4, when Yumoto says cuddling Wombat brings him close to Nirvana, En compares the feeling to Linus' blanket.
- Another one from episode 4: Atsushi mentions an eighteen-year-old savior of the century with seven stars on his back, among other roles by Shozo Iizuka.
- Episode five had Atsushi in the library. When picking a book his hand goes over a couple of volumes titled Grand Thief Actor.
- Death Note:
- In Episode 6, the music when Akoya visits the Defense Club room is very like the tense music when Atsushi is concealing the body of the dead teacher.
- And when En delivers an I-know-something-you-don't joke at Akoya's expense, he's sporting a huge bag... of potato chips.Akoya: That stench ... Is there a dead animal here?
En: You've got the right idea.
- En is also the one who flourishes a bunch of top grades in this episode, somehow.
- The music from episode 6 returns in episode 7 to underscore Io's toothbrush investigation.
- Episode 7 practically name-drops Detective Conan (albeit bleeped) and even features the iconic doors from the anime adaptation as the episode's eyecatch. Exact dialogue of the name drop:Io: There's been an incident.Yumoto: A murder?!Atsushi: Now, now. This isn't Detective *bleep*nan.
- Episode 8's monster resembles a Heartless once it loses its kotatsu shell.
- The traps the melon monster in episode 9 sets for the Battle Lovers are all found in Takeshi's Castle.
- The ending reveals that Boueibu is a galactic Truman Show of sorts.
- Not to mention its resemblance to a certain South Park episode.
- The episode when they have the discussion in a hot spring over who took Io's toothbrush was an episode's "conflict" in Gakuen Heaven.
- Season 2 episode 5 is sprinkled with references to Haikyuu!! (the volleyball ones) and Aim for the Ace! (Munakata and the Monster of the Week's name origins). The Monster of the Week is voiced by Daisuke Namikawa, who is also responsible for the voice of Toru Oikawa in the aforementioned Haikyuu.
- When the Beppus are shown in space school and their space home, there are lots of circular glowing items that appear in the background◊. These are known as Matsumoto meters and are a reference to the Leijiverse.
- The Student Council's uniforms as exchange students in season 2 are a reference to a certain manga called Kaze to Ki no Uta.
- The stage play gives us Mayao Kitajima (and another character who is a reference to Robert De Niro).
Shout Out / Cute High Earth Defense Club LOVE!