Mirai Kuriyama has a habit of cleaning her glasses when she is nervous or wants to change the topic, even making the motion when she isn't wearing them.
Seemingly random scenes of Akihito running through a flooded room and escaping a huge explosion in the opening theme are not observed in this series. Those actually happen in the sequel movie Kyôkai no Kanata: mirai-hen (2015)
Hiroomi states that he submitted an application for Mitsuki to become a HND48 member. This is a parody of the idol group AKB48.
In the bonus episodes of Mini Theater in the Blu-ray edition, it is mentioned Izumi is the one who kills the Youmu on the school rooftop after the groups failed attempts.
Hiroomi likes to call Akihito "Akkey". Akihito doesn't like it since, according to him, it sounds like the nickname of a washed up idol.