That Time I Got Reincarnated as a Slime the Movie: Scarlet Bond

Tensei Shitara Slime Datta Ken: Guren no Kizuna-hen• 劇場版 転生したらスライムだった件 紅蓮の絆編

A long-running conspiracy is swirling over a mysterious power known as “Queen” in Raja, a small country west of Tempest. When a slime who evolved into a Demon Lord named Rimuru Tempest crosses paths with Hiiro, a survivor of the Ogre race, an incredible adventure packed with new characters begins. The power of bonds will be put to the test!

(Source: Crunchyroll)