User blog comment:TheIrregularOne/Why not OVAs?/@comment-7719364-20131222025135

I disagree. OVAs stand for Original Video Animations, meaning they're usually bundled on a DVD with something else, like a light novel volume. Furthermore, OVAs tend to be original content made by the studio themselves, not the author, as strictly extra content, like a fanservice beach episode or something. Major canon events would not be placed in OVAs.

Also, as i recall, NT4 was Baggage City right? I'm guessing one of the reasons you felt it would be suitable for a movie or OVA is because until around the end, the story felt detached and for the most part, wasn't from the perspective of Touma. It wasn't until about 2/3 into the story that things tie into the GREMLIN story arc and Touma regained the central role in the story.

What I believe to be most appropriate for this is to have WW3 end with a season 4 of the anime, and season 1 of NT will end with Hawaii. Season 2 of NT will begin with Baggage City, since placing Baggage City in the middle of a different season may feel abrupt with the main focus of the story shifting from Touma to someone else.