Sometimes, you watch anime series and a few episodes in you realize that it is based off a densely lore-packed light novel without even needing to look it up. That was the case for me with The Irregular at Magic High School. Information in the anime is packed on in there, and there is really so much more that is skipped when it comes to the source material.
When it comes to adapting the light novel, The Irregular At Magic High School anime tends to jump around a fair bit. However, the very simple answer to what is a complex question is to start at Novel 12 if you finished season 2 though you’ll note that the prologue of Novel 12 was adapted. This starting point also accounts for the recent Reminiscence special.
Why was that a complex question? Well, season one covered Novels 1 through 7 (skipping Novel 5), season two covered Novels 9 through 11, and the Reminiscence Special adapted Novel 8. The jumpiness of the adaptation is part of the reason to just read the light novels at the beginning, but mostly is because you miss tons of information and picking up the series at Novel 12 can make getting into the series needlessly hard to figure out.
As for if you should go back and read the skipped Novel 5, it is just a collection of short stories. One does have bearing on the plot, but if you are already jumping in at Novel 12, you’ve missed so much already that the clarity there won’t make much difference.
The Irregular at Magic High School also has a manga, and that can be a bit easier to get into. The manga is separated into the separate arcs of the series. So in the case of finishing season two of the anime, you would start at the next manga arc series, which is the Double Seven arc. I’ve never found all the arcs grouped together, so treat them as separate series. You may also wish to seek out the Natsuyasumi-hen and Kaichou Senkyou-hen manga series, which covers the light novel volume that the anime skipped.
Now finally, we have The Honor Student at Magic High School series. This one is more simple. You can pick up the series at Novel 5 of the spin-off light novel series or Chapter 78 of the manga.
TL;DR Summary
The Irregular at Magic High School Anime (2 seasons)+Movie+Reminiscence Special – Light Novel After Anime Start – Novel 12
The Irregular at Magic High School Anime (2 seasons)+Movie+Reminiscence Special – Manga After Anime Start – Double Seven Arc series
The Honor Student at Magic High School Light Novel and Manga Start – Start at Light Novel 5 or Manga Chapter 78
