Following yesterday’s trailer for Wave 4 of the Three Houses DLC, Nintendo Japan posted an article with a few more details.

To get everyone up to speed, Wave 4 will be arriving on 12th or 13th February 2020 (depending on where you live). It will include a new side story called “Cindered Shadows” and features new characters, classes, paralogues and activities etc.

The first thing to note is that Cindered Shadows is separate from the main game, with its own save files. To play it, you must choose the new “Side Story” option located between “Nintendo eShop” and “Copy”.
When creating a save file, players can choose the protagonist’s form and name, as well as select the difficulty (Normal or Hard) and mode (Classic or Casual). Just like when you begin a new save file for the main game.
In the main game, players followed a monthly routine where they taught and socialised with their students, while preparing for the end-of-month task. However, Cindered Shadows will have a different gameplay cycle (no details given).
Also, players will be provided with fixed team members and won’t be able to recruit other students. Furthermore, the maps will feature a lot of gimmicks and the overall difficulty is a bit higher than the main game.
(Not mentioned here, but by playing the side story, you can recruit new characters from the side story in the main game.)
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