It’ll operate under the name The Ancient Magus’ Bride: The Boy From the West and the Knight of the Mountain Haze.
We had a really good run with the anime adaptation of The Ancient Magus’ Bride previously and honestly, I don’t think most people expected more to come.
Known as Mahou Tsukai no Yome in its original Japanese form, Seven Seas Entertainment acquired The Ancient Magus Bride manga back in 2014 for release.
The second OAD for next March now has its first trailer landing which you can see below.