This is not a mainline Dragon Quest game. It’s a licensed manga adaptation turned RPG, developed by Matrix Corporation and published by Enix .

is finally receiving its first official English localization by Square Enix Manga & Books Kanzenshuu

While Toriyama’s designs rule the games, Kawamata’s writing is often cited by Dragon Quest developers as supplementary canon. The manga explains why the Dragonlord hates humanity and how the Princess of Moonbrooke’s lineage was cursed.