That one is called Isekai Musuo, which certainly got fans speculating if this is an original title or a massive crossover between Isekai anime, much like their Gundam Musuo, Hyrule Musuo, and Fire Emblem Musuo games.
And now, it has been reported that they have trademarked several new Musuo titles, but one of them got fans really talking.
Koei Tecmo is best known for their Dynasty Warriors games AKA the Musuo games.
That includes Isekai Musuo too, so don’t get your hopes up too much that it’s getting released by next year or so.