Remember that Captain Toad: Treasure Tracker promotion Nintendo ran last year that was exclusive to Switch Online subscribers? In case you forgot, it allowed users of the service to play the game for free for a 10-day period.
This title was released in 2017 by Koei Tecmo and didn't get quite as much time to shine as certain other releases. Fire Emblem Warriors will become available to Japanese Switch Online subscribers for one week, from 20th January through to the 26th of January.
Like Captain Toad, users will be able to play through the entire game from start to finish and save data will carry across to the main game if the user decides to purchase it once the online promotion has ended. There'll also be a sale for this game and its DLC (40% off) until the start of next month.
If Nintendo announces something similar here in the west, we'll be sure to let you know.