- Author Existence Failure:
- Takeshi Aono, Axel Thurston's VA, died of complications from a stroke in 2012 before production of the Hi-Evolution trilogy. This may play a part in why he did not appear or was even referenced in the first film.
- Dewey's voice actor, Kouji Tsujitani, succumbed to a stroke in October 2018, and was replaced by Keiji Fujiwara (Holland's actor) beginning with Anemone. Fujiwara himself would sadly pass away due to cancer on April 12, 2020, a year before the final film would be scheduled to release.
- The Other Darrin:
- Japan wise, the first film came out when Keiji Fujiwara was still on hiatus for health reasons resulting in Toshiyuki Morikawa taking his place as Holland.
- While Funimation and New Generation Pictures managed to reunite most of the original cast for the first 2 films, there were still some cases of this. Matthieu's brief appearance in the first film is voiced by Max Lawrence (instead of Kirk Thornton) & Bill Rogers takes over as both Uno in the first film (from Dan Woren) and as Dr. Bear (from Joey Camen) in Anemone.
- Role Reprise: The vast majority of the English cast was brought back together, an especially notable feat when VAs like Kim Strauss (Dewey), Michael Forest (Blair) and Peter Doyle (Dominic) have not been very active in anime/voice acting in the years between the original series and these films.
- Schedule Slip: The trilogy were slated to release one film a year from 2017 to 2019. While the first 2 films managed to stick to schedule, the final movie was delayed to 2021.
Trivia / Eureka Seven Hi-Evolution